1.1 Preface
...
1-1
1.2 Benefits and Features
...
1-2
1.2.1 Large Capacity and High Integration
...
1-2
1.2.2 Powerful Multicast Services
...
1-3
1.2.3 Smart Triple Play Solutions
...
1-3
1.2.4 Superb Service Wholesale Solutions
...
1-4
1.2.5 Abundant Ports
...
1-4
1.2.6 Guaranteed QoS
...
1-5
1.2.7 Comprehensive User Management
...
1-5
1.2.8 Flexible Networking
...
1-6
1.2.9 Carrier-Class Reliability
...
1-6
1.2.10 Strict Security
...
1-6
1.2.11 Superior Maintainability and Manageability
...
1-7
1.3 External Ports
...
1-8
1.3.1 Subscriber Ports
...
1-8
1.3.2 Network Ports
...
1-9
1.3.3 Management Ports
...
1-9
1.3.4 Test Ports
...
1-10
Chapter 2 System Architecture
...
2-1
2.1 Functional Architecture
...
2-1
2.1.1 Main Control Module
...
2-1
2.1.2 ADSL2+ Module
...
2-2
2.1.3 SHDSL Module
...
2-2
2.1.4 Ethernet Module
...
2-2
2.1.5 ISU Module
...
2-2
2.1.6 Environment Monitor Module
...
2-3
2.2 Hardware Architecture
...
2-3
2.2.1 Cabinet
...
2-3
2.2.2 MA5600 Frame
...
2-6
2.2.3 Boards, Subboards and Ports
...
2-8
2.3 Software Architecture
...
2-10
Chapter 3 Service Functions
...
3-1
3.1 Broadband Access Services
...
3-1
3.1.1 ADSL2+ Service
...
3-1
3.1.2 SHDSL Service
...
3-3
3.2.4 Super VLAN
...
3-5
3.2.5 QinQ VLAN
...
3-6
3.2.6 VLAN Stacking
...
3-6
3.3 Multicast Services
...
3-7
3.3.1 IGMP Proxy
...
3-7
3.3.2 Managed Multicast
...
3-8
3.4 MAC Address Management
...
3-8
3.5 Built-in ISU
...
3-9
3.6 Routing Management
...
3-9
3.7 ARP and ARP Proxy
...
3-11
3.8 STP/RSTP
...
3-12
3.9 QoS
...
3-13
3.9.1 Flow Classification
...
3-13
3.9.2 DiffServ Service
...
3-13
3.9.3 Traffic Policing and Port Rate Limit
...
3-13
3.9.4 Queue Scheduling
...
3-14
3.10 Terminal Management
...
3-15
3.11 Environment Monitoring
...
3-16
Chapter 4 Networking Applications
...
4-1
4.1 System Networking
...
4-1
4.1.1 IP-DSLAM Application
...
4-1
4.1.2 Built-in ISU Application
...
4-2
4.1.3 Subtending Application
...
4-4
4.2 Typical Applications
...
4-5
4.2.1 QinQ Application
...
4-5
4.2.2 VLAN Stacking Application
...
4-6
4.2.3 Triple Play Application
...
4-7
4.2.4 Residential Community Application
...
4-9
4.2.5 IP Hotel Application
...
4-10
Chapter 5 Management and Maintenance
...
5-1
5.1 System Maintenance
...
5-1
5.2 CLI Mode
...
5-2
5.2.1 Running Environment
...
5-2
5.2.2 Characteristics
...
5-2
5.2.3 Networking
...
5-3
5.3 NMS Mode
...
5-3
Chapter 6 Technical Specifications
...
6-1
6.1 Physical Specifications
...
6-1
6.1.1 Device Dimensions
...
6-1
6.1.2 Device Weight
...
6-1
6.1.3 Power Specifications
...
6-2
6.1.4 Environment Conditions
...
6-2
6.1.5 Power Consumption
...
6-2
6.2 Performance Specifications
...
6-3
6.2.1 System Performance
...
6-3
6.2.2 System Configurations
...
6-3
6.2.3 Reliability indexes
...
6-4
6.2.4 Service Characteristics
...
6-4
6.3 Port Specifications
...
6-11
6.3.1 Console Port
...
6-11
6.3.2 ADSL2+ Port
...
6-11
6.3.3 SHDSL Port
...
6-12
6.3.4 FE Electrical Port
...
6-12
6.3.5 FE Single-Mode Optical Port
...
6-12
6.3.6 FE Multi-mode Optical Port
...
6-13
6.3.7 GE Single-mode Optical Port
...
6-14
6.3.8 GE Multi-mode Optical Port
...
6-14
6.3.9 GE Electrical Port
...
6-15
6.4 Standards Compliance
...
6-15
Appendix A Introduction to xDSL Technology
...
A-1
A.1 Overview
...
A-1
A.1.1 Introduction to xDSL Technologies
...
A-1
A.1.2 Specifications of xDSL Technologies
...
A-3
A.2 ADSL2+
...
A-4
A.3 SHDSL
...
A-9
Appendix B Environment Requirements
...
B-1
B.1 Storage Requirements
...
B-1
B.2 Transportation Requirements
...
B-3
B.3 Running Environment Requirements
...
B-5
Appendix C Acronyms and Abbreviations
...
C-1
HUAWEI
SmartAX MA5600 Multi-service Access Module
Technical Manual
Technical Manual
Manual Version T2-050228-20050203-C-3.10
Product Version V300R001
BOM 31026528
Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. Please feel free to contact our local office or company headquarters.
Huawei Technologies Co., Ltd.
Address: Administration Building, Huawei Technologies Co., Ltd., Bantian, Longgang District, Shenzhen, P. R. China Postal Code: 518129
Website: http://www.huawei.com
Copyright © 2005 Huawei Technologies Co., Ltd.
All Rights Reserved
No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.
Trademarks
, HUAWEI, C&C08, EAST8000, HONET, , ViewPoint, INtess, ETS, DMC, TELLIN, InfoLink, Netkey, Quidway, SYNLOCK, Radium, M900/M1800, TELESIGHT, Quidview, Musa, Airbridge, Tellwin, Inmedia, VRP, DOPRA, iTELLIN, HUAWEI OptiX, C&C08iNET, NETENGINE, OptiX, iSite, U-SYS, iMUSE, OpenEye, Lansway, SmartAX, infoX, and TopEng are trademarks of Huawei Technologies Co., Ltd.
All other trademarks and trade names mentioned in this manual are the property of their respective holders.
Notice
The information in this manual is subject to change without notice. Every effort has been made in the preparation of this manual to ensure accuracy of the contents, but all statements, information, and recommendations in this manual do not constitute the warranty of any kind, express or implied.
Release Notes
The current version of this manual applies to the SmartAX MA5600 Multi-service Access Module V300R001.
Related Manuals
The following manuals provide information about the MA5600.
Manual Content
SmartAX MA5600
Multi-service Access Module Technical Manual
It provides an overall introduction to the MA5600, including the major functions, system structure, service implementation, management & maintenance, networking & applications.
SmartAX MA5600 Multi-service Access Module Operation Manual
It is used for assisting the users in general operations, data configurations and typical applications of the MA5600.
SmartAX MA5600 Multi-service Access Module Command Help
It introduces all commands available in the MA5600, as well as the command usage and examples. It is only available in electronic form.
SmartAX MA5600 Multi-service Access Module Installation Manual
It provides information on the system installation of the MA5600.
Documentation CD ROM It contains the package of documentation.
Organization
The manual assists the users in understanding, operating and maintaining the MA5600. There are seven parts in this manual, including:
Chapter 1 System Overview profiles the features of the MA5600, and introduces the
external interfaces of the MA5600.
Chapter 2 System Architecture introduces the hardware architecture of the MA5600,
including its boards, power supply and heat dissipation system. This chapter also briefs the software architecture of the MA5600.
Chapter 4 Networking Applications introduces various networking applications of
the MA5600.
Chapter 5 Management and Maintenance deals with the CLI-based and
SNMP-based network management systems of the MA5600.
Chapter 6 Technical Specifications gives technical specifications about the MA5600. Appendix gives environment requirements of the MA5600, as well as a list of
abbreviations and acronyms that appear in this manual.
Intended Audience
The manual is intended for the following readers: z Network administrators
z Network engineers
Conventions
The manual uses the following conventions:
I. General conventions
Convention Description
Arial Normal paragraphs are in Arial.
Boldface Headings are in Boldface.
II. Symbols
Eye-catching symbols are also used in the manual to highlight the points worthy of special attention during the operation. They are defined as follows:
Caution: Means reader be extremely careful during the operation. Note: Means a complementary description.
Table of Contents
Chapter 1 System Overview ... 1-1
1.1 Preface... 1-1 1.2 Benefits and Features... 1-2 1.2.1 Large Capacity and High Integration ... 1-2 1.2.2 Powerful Multicast Services ... 1-3 1.2.3 Smart Triple Play Solutions... 1-3 1.2.4 Superb Service Wholesale Solutions... 1-4 1.2.5 Abundant Ports... 1-4 1.2.6 Guaranteed QoS ... 1-5 1.2.7 Comprehensive User Management ... 1-5 1.2.8 Flexible Networking... 1-6 1.2.9 Carrier-Class Reliability... 1-6 1.2.10 Strict Security ... 1-6 1.2.11 Superior Maintainability and Manageability ... 1-7 1.3 External Ports ... 1-8 1.3.1 Subscriber Ports... 1-8 1.3.2 Network Ports... 1-9 1.3.3 Management Ports... 1-9 1.3.4 Test Ports ... 1-10
Chapter 2 System Architecture... 2-1
2.1 Functional Architecture ... 2-1 2.1.1 Main Control Module ... 2-1 2.1.2 ADSL2+ Module ... 2-2 2.1.3 SHDSL Module... 2-2 2.1.4 Ethernet Module... 2-2 2.1.5 ISU Module... 2-2 2.1.6 Environment Monitor Module ... 2-3 2.2 Hardware Architecture ... 2-3 2.2.1 Cabinet ... 2-3 2.2.2 MA5600 Frame... 2-6 2.2.3 Boards, Subboards and Ports ... 2-8 2.3 Software Architecture ... 2-10
Chapter 3 Service Functions... 3-1
3.1 Broadband Access Services... 3-1 3.1.1 ADSL2+ Service... 3-1
3.1.3 LAN Service ... 3-4 3.2 VLAN Services... 3-4 3.2.1 Standard VLAN ... 3-4 3.2.2 MUX VLAN ... 3-5 3.2.3 Smart VLAN ... 3-5 3.2.4 Super VLAN ... 3-5 3.2.5 QinQ VLAN... 3-6 3.2.6 VLAN Stacking ... 3-6 3.3 Multicast Services... 3-7 3.3.1 IGMP Proxy ... 3-7 3.3.2 Managed Multicast ... 3-8 3.4 MAC Address Management... 3-8 3.5 Built-in ISU ... 3-9 3.6 Routing Management ... 3-9 3.7 ARP and ARP Proxy... 3-11 3.8 STP/RSTP ... 3-12 3.9 QoS... 3-13 3.9.1 Flow Classification... 3-13 3.9.2 DiffServ Service... 3-13 3.9.3 Traffic Policing and Port Rate Limit... 3-13 3.9.4 Queue Scheduling... 3-14 3.10 Terminal Management... 3-15 3.11 Environment Monitoring... 3-16
Chapter 4 Networking Applications... 4-1
4.1 System Networking... 4-1 4.1.1 IP-DSLAM Application... 4-1 4.1.2 Built-in ISU Application... 4-2 4.1.3 Subtending Application ... 4-4 4.2 Typical Applications ... 4-5 4.2.1 QinQ Application ... 4-5 4.2.2 VLAN Stacking Application ... 4-6 4.2.3 Triple Play Application... 4-7 4.2.4 Residential Community Application... 4-9 4.2.5 IP Hotel Application... 4-10
Chapter 5 Management and Maintenance ... 5-1
5.1 System Maintenance ... 5-1 5.2 CLI Mode ... 5-2 5.2.1 Running Environment... 5-2 5.2.2 Characteristics... 5-2 5.2.3 Networking ... 5-3 5.3 NMS Mode ... 5-3
5.3.1 Running Environment... 5-3 5.3.2 Characteristics... 5-4 5.3.3 Networking ... 5-5
Chapter 6 Technical Specifications... 6-1
6.1 Physical Specifications ... 6-1 6.1.1 Device Dimensions ... 6-1 6.1.2 Device Weight ... 6-1 6.1.3 Power Specifications... 6-2 6.1.4 Environment Conditions ... 6-2 6.1.5 Power Consumption... 6-2 6.2 Performance Specifications ... 6-3 6.2.1 System Performance... 6-3 6.2.2 System Configurations ... 6-3 6.2.3 Reliability indexes... 6-4 6.2.4 Service Characteristics ... 6-4 6.3 Port Specifications ... 6-11 6.3.1 Console Port... 6-11 6.3.2 ADSL2+ Port ... 6-11 6.3.3 SHDSL Port... 6-12 6.3.4 FE Electrical Port... 6-12 6.3.5 FE Single-Mode Optical Port... 6-12 6.3.6 FE Multi-mode Optical Port ... 6-13 6.3.7 GE Single-mode Optical Port ... 6-14 6.3.8 GE Multi-mode Optical Port ... 6-14 6.3.9 GE Electrical Port... 6-15 6.4 Standards Compliance ... 6-15
Appendix A Introduction to xDSL Technology ...A-1
A.1 Overview...A-1 A.1.1 Introduction to xDSL Technologies...A-1 A.1.2 Specifications of xDSL Technologies ...A-3 A.2 ADSL2+ ...A-4 A.3 SHDSL...A-9
Appendix B Environment Requirements ...B-1
B.1 Storage Requirements ...B-1 B.2 Transportation Requirements...B-3 B.3 Running Environment Requirements ...B-5
Appendix C Acronyms and Abbreviations ...C-1 Index ... i-1
Chapter 1 System Overview
1.1 Preface
As the demand for telecom services keeps growing, provisioning of integrated data, video, voice and multimedia services that feature large capacity, high data rate, great bandwidth and good quality has become a new direction in access network development. In light of global users’ requirements, Huawei has launched its SmartAX MA5600 Multi-service Access Module.
The MA5600 employs non-blocking gigabit switching fabric (1 Gbit/s per line board), facilitating rich access means such as:
z Asymmetric Digital Subscriber Line 2 Plus (ADSL2+) z Single-line High Speed Digital Subscriber Line (SHDSL) z Ethernet
The MA5600 features high density of subscriber ports, diverse interfaces and flexible networking modes. For residential users, it supports services such as web surfing, Internet gaming and video on demand (VOD). For commercial users, it supports a variety of services with guaranteed quality of service (QoS), such as video conferencing, enterprise Intranet, virtual private network (VPN), and packetized voice transmission.
Moreover, the MA5600 supports the following functions to ease the operators’ effort to build up, operate and maintain a broadband access network:
z Intelligent Service Unit (ISU) z Centralized terminal management z Broadband test
Figure 1-1 shows the networking of the MA5600 under centralized management of the Huawei iManager N2000 network management system (iManager N2000).
BRAS IP network iManager N2000 ADSL2+/FE/SHDSL FE/GE FE/GE FE/GE FE/GE
MA5600 MA5600 MA5600
MA5600
ADSL2+ /SHDSL/FE ADSL2+/SHDSL/FE ADSL2+ /SHDSL/FE
Figure 1-1 Networking of the MA5600
1.2 Benefits and Features
The MA5600 provides rich services and management methods, including: z DSLAM access services
z Multicast services z Triple play services z Private line services
With its strict guarantee of QoS and powerful access control list (ACL) functions, the MA5600 offers diverse, operable and manageable broadband access services.
1.2.1 Large Capacity and High Integration
The MA5600 integrates data switching, routing and user management. This helps to enhance the system integration.
In addition, to satisfy medium and large capacity requirements, the MA5600: z Adopts large capacity backplane with non-blocking GE bus.
– The backplane capacity is 210 Gbit/s. – The packet forwarding rate is 72 Mpps.
z Supports high-density line boards, such as 64-port ADSL2+ board and 32-port SHDSL board.
z Each frame provides 896 ADSL2+ lines or 448 SHDSL lines.
z Each cabinet houses three frames, providing 2688 ADSL2+ lines or 1344 SHDSL line.
1.2.2 Powerful Multicast Services
The MA5600 is able to support carrier-class multicast service operation. The MA5600 supports multicast protocols and managed multicast, assisting carriers in provisioning and managing value-added broadband multicast services.
To be more specific, the MA5600 supports:
z Internet Group Management Protocol (IGMP) Proxy multicast and profile-based managed multicast with up to 1000 multicast groups
z Rich authentication modes for different multicast operations z Single-PVC and multi-PVC multicast
z Video traffic received from multiple uplink ports
z Channel preview with configurable preview times in one day z Viewership statistics
z IGMP pre-join, fast-leave as well as IGMP high performance processing for broadband TV (BTV) over xDSL
With the managed multicast function, the MA5600 can control the multicast group that a user can join. Working with the operation support system (OSS) through the TL1 interface on the network management system (NMS), the MA5600 offers a solution to user authority control for the multicast service providers.
1.2.3 Smart Triple Play Solutions
The MA5600 supports smart triple play solutions to provide Voice over IP (VoIP), Internet access and BTV. A built-in ISU or an external broadband remote access server (BRAS) can be used to manage these services.
z Built-in ISU
In the MA5600, the built-in ISU is a service board plugged in the frame. The ISU functions as the service gateway for triple play.
z External BRAS
With an external BRAS, triple play users are accessed to the MA5600 through the Home Gateway. The MA5600 then connects these users to the upstream BRAS transparently for unified management.
1.2.4 Superb Service Wholesale Solutions
The MA5600 can coordinate with the ISU to provide service wholesale in various modes. Major access modes of service wholesale include:
z Layer 2 Tunneling Protocol (L2TP) mode
In this mode, the ISU functions as the L2TP access concentrator (LAC). The MA5600 accesses the wholesale users, and identifies these users by VLAN IDs. The ISU will then connect the users to various Internet service providers (ISPs) based on their domain names.
z Generic Routing Encapsulation (GRE) mode
In this mode, the ISU terminates the users and accesses them to different ISPs through GRE tunnels based on their domain names.
z 802.1q in 802.1q (QinQ) mode
In this mode, when receiving packets with private VLAN tag from the lower layer, the MA5600 adds public network VLAN tags to these packets, and then sends them to the corresponding ISPs.
1.2.5 Abundant Ports
The MA5600 can offer various network ports, service ports, maintenance ports and test ports to adapt to different network applications. The ports provided by the MA5600 are open to and compatible with industry standards.
See Table 1-1.
Table 1-1 Ports provided by the MA5600
Type Port Remarks
FE optical/electrical port
Network port
GE optical/electrical port
Both the GE and FE optical ports adopt the SFP optical module. The SFP module can be a single-mode module or a multi-mode module, depending on the required reaches.
Service port ADSL2+
Fully compatible with ADSL, with added advantages of:
z Higher data rate z Longer signal reach z Lower power consumption z More stable operation
z Support of single and dual ended loop test
Type Port Remarks
SHDSL
It adopts symmetric data transmission. It transmits at 192 kbit/s – 2312 kbit/s in both the upstream and the downstream over a reach of 3000–6000 m.
Ethernet It allows data burst and is delay insensitive. It transmits at 100 Mbit/s. Serial port
Ethernet
maintenance port
The ports are used for local and remote maintenance.
Maintenance port
Environment monitor port
Environment parameters collected by the monitoring device are reported to the host through this port.
Test port Line test port It is open and standardized, enabling connection with external test devices to carry out xDSL line tests.
1.2.6 Guaranteed QoS
The MA5600 offers customized QoS based on different services and user requirements. The MA5600 supports:
z Traffic rule-based packet filtering, packet redirection, flow mirroring, traffic statistics, traffic policing, queue scheduling on a port, rate limit on a port, priority strategies, and VLAN change strategies.
z 802.1p-based class of service (CoS) and traffic prioritization. 802.1p is used by default.
z Various queue scheduling algorithms, such as strict priority (SP) and weighted round robin (WRR).
1.2.7 Comprehensive User Management
The MA5600 supports the following user management means:
z Remote Authentication Dial In User Service (RADIUS) accounting z User management based on port and MAC address
z Multicast authority control on the users
z Management of address resolution and routing z Policy Information Transfer Protocol (PITP)
With PITP, the MA5600 carries the location information of a user port in the PPPoE authentication request sent to the BRAS. In this way, the MA5600 enables binding
between the user account and the user port, which is helpful for identifying the broadband service users.
z User management functions facilitated by the ISU
With the ISU board, the MA5600 supports L2TP and authentication based on PPPoE, PPPoA, VLAN binding, and VLAN+Web (forced portal and embedded portal). It also supports accounting based on traffic volume or online duration, offering a bypass access solution for commercial users.
z PPPoA-to-PPPoE conversion z IPoA-to-IPoE conversion
z Dynamic Host Configuration Protocol (DHCP) Relay z DHCP Option60
z ARP Proxy
z Layer 3 forwarding, facilitating both static routing and dynamic routing (such as RIP based and OSPF based routing)
1.2.8 Flexible Networking
The MA5600 supports various networking modes to cater for the service requirements of various locations and applications. It supports the following networking modes : z xDSL-based IP DSLAM networking
z Subtending networking through Ethernet ports
z Triple play networking with unified user management functions
z QinQ and VLAN stacking networking, allowing private line interconnection service and VLAN extension
1.2.9 Carrier-Class Reliability
To ensure operation security, the MA5600 adopts carrier-class reliability design in that: z All boards are hot-swappable.
z The SCU supports active/standby switchover. z The ADSL2+ port supports N+1 backup.
z The upstream links can be backed up to enhance the system reliability.
z The system is self-healing, offering more than 150,000 hours of mean time between failures (MTBF).
z The system offers diverse alarm information, and adopts lightning proof and anti-interference design.
1.2.10 Strict Security
z L2 user isolation and controlled mutual access
z Restriction on the number of multicast groups allowed for each port z Restriction on the number of hosts allowed to access each port z Query of port IP address by MAC address
z Binding between the MAC address and port z Binding between the IP address and port
z Protection of DHCP server to enhance DHCP security
z DHCP option82, enabling authentication of the type of the customer premises equipment (CPE)
z RADIUS authentication of the management users z Binding between the user account and port z ACL-based access control
1.2.11 Superior Maintainability and Manageability
The MA5600 features excellent management, maintenance, monitoring and test functions, greatly easing fault locating and routine management.
z The MA5600 can be managed on a local or remote terminal, or through the centralized NMS.
z The MA5600 supports network management through the command line interface (CLI), or inband/outband NMS such as the iManager N2000 based on Simple Network Management Protocol (SNMP). iManager N2000 NMS provides graphical user interface (GUI) for centralized management of the MA5600.
z The MA5600 enables you to manage the remote transmitting units (RTUs) in a centralized manner. On the MA5600, you can:
– Query the RTU information. – Monitor the status of the RTUs. – Configure the RTU data. – Bind the RTUs.
– Upgrade the RTU software.
z The MA5600 provides complete alarm, test, diagnosis, and tracking functions. This can greatly ease your daily maintenance and management, boost network operation reliability, and ensure network QoS.
z The MA5600 provides xDSL line test ports. You can carry out line selection and fault locating through these ports and the broadband line test system.
z The MA5600 collects environment information through its environment monitor module to facilitate unattended maintenance. The information shows the temperature and humidity of the machine room, the power supply voltage, and the smoke alarms.
z The MA5600 uses fans for heat dissipation. Each fan has indicators telling the fan’s running states. Each fan can be mounted and removed independently.
1.3 External Ports
External ports include subscriber ports, network ports, management ports, and test ports.
1.3.1 Subscriber Ports
The MA5600 provides a variety of subscriber ports, including ADSL2+, SHDSL, and FE/GE ports.
I. ADSL2+ port
Compliant with ITU-T G.992.3 and G.992.5, the ADSL2+ port provides twisted-pair based ADSL2+ access in coordination with the ATU-R. (ATU-R is short for ADSL Transmitting Unit-Remote End).
II. SHDSL port
Compliant with ITU-T G.991.2 (Annex A and Annex B), the SHDSL port provides twisted-pair based SHDSL access in coordination with the STU-R. (STU-R is short for SHDSL Transmitting Unit-Remote End).
III. FE/GE port
The GE/FE ports of the MA5600 can be used as either subscriber ports or network ports. When GE/FE ports are used as subscriber ports, the MA5600 can connect with a LAN switch over optical fiber or Category-5 twisted pairs to provide Ethernet access. Three types of FE/GE ports are available: FE/GE electrical port, FE/GE single-mode optical port and FE/GE multi-mode optical port.
z The FE/GE electrical port uses an RJ45 connector.
When an electrical port connects with a small capacity L2 switch through Category-5 twisted pairs, the reach shall be within 100 m.
z The FE single-mode/multi-mode optical port uses an LC optical connector. The port connects with an optical distribution frame (ODF) using the dedicated tail fiber and then connects to the LAN Switch through optical fibers. The FE multi-mode port supports a reach of 2 km. The FE single-mode port supports a reach of 15 km.
z The GE single-mode/multi-mode optical port uses an LC optical connector. The port connects with an ODF using the dedicated tail fiber and then connects to the LAN Switch through optical fibers. The GE multi-mode port supports a reach of
1.3.2 Network Ports
The MA5600 provides multiple network ports such as FE and GE ports.
I. FE port
Three kinds of FE ports are available: z FE electrical port
z FE single-mode optical port z FE multi-mode optical port
The port cabling is the same as that at the subscriber end. FE ports enable the MA5600 to connect with upstream devices, or with other subtended MA5600 frames.
II. GE port
Three types of GE ports are available: z GE electrical port
z GE single-mode optical port z GE multi-mode optical port
GE ports enable the MA5600 to connect with upstream devices, or with other subtended MA5600 frames.
1.3.3 Management Ports
The MA5600 provides multiple management and maintenance ports. With these ports, you can maintain the MA5600 locally and remotely in command line interface (CLI) mode or network management system (NMS) mode.
I. Serial port
The SCU board on the MA5600 provides an RJ-45 serial port (CON) for both local and remote maintenance. The default baudrate of the serial port is 9600 bit/s.
The port can be used for CLI operations, system commissioning or fault locating. The cable connecting the serial port and the local maintenance PC has a DB9 connector on one end, and an RJ45 connector on the other end.
II. Ethernet Maintenance port
The SCU board on the MA5600 provides an RJ-45 Ethernet port (ETH) for both local and remote maintenance. The port is 10/100M auto-sensing.
The port can connect with local maintenance PC or remote NMS for program loading, debugging and other operations.
III. Environment monitor port
The SCU board on the MA5600 provides an RJ-45 environment monitor port (MON) to connect with the environment monitor module through a special monitoring cable. It collects various environment parameters sent from the environment monitor module, including temperature, humidity, power voltage and smoke. Besides, there is also a fan monitor port on the backplane.
1.3.4 Test Ports
The MA5600 supports line capture function through the external or internal line test bus. You can use its broadband test ports to interface with an external tester to implement xDSL line tests.
Chapter 2 System Architecture
This chapter describes the functional architecture, hardware architecture and software architecture of the MA5600.
2.1 Functional Architecture
The MA5600 adopts modularized design, in which the functional modules are independent of each other. All these modules provide standard interfaces, and have good scalability in terms of system capacity and service types.
The MA5600 consists of multiple functional modules as shown Figure 2-1.
FE/GE
GE GE GE
RS-232
Main control module/ Ethernet module
ADSL2+ module SHDSL module ISU module
Figure 2-1 Functional modules of the MA5600
The following sections describe these modules in detail.
2.1.1 Main Control Module
Consisting of the SCU board, subboards and related software, the main control module:
z Carries out the control, management and service switching of the MA5600. z Carries out all L2/L3 switch functions supported by Ethernet protocols.
z Provides two slots on the front panel to hold the optical or electrical FE/GE network port subboards.
z Provides serial port and Ethernet port for maintenance and management. z Supports switchover between the active and standby SCU board.
2.1.2 ADSL2+ Module
The ADSL2+ module consists of the ADBF board, ADEF board, splitter (SPL) board and associated software. The SPL board separates voice signals from ADSL2+ signals, and sends ADSL2+ signals to the ADSL2+ board. The ADSL2+ board provides 64 ADSL2+ subscriber lines for accessing the ADSL Transmitting Unit-Remote end (ATU-R).
2.1.3 SHDSL Module
The SHDSL module consists of the SHEA board and associated software. This module provides 32 SHDSL subscriber lines for accessing the STU-R through twisted pair lines. (STU-R stands for SHDSL Transmitting Unit-Remote end.)
The SHDSL solution aims at serving medium and small enterprises and SOHO users.
2.1.4 Ethernet Module
The FE and GE ports on the SCU, apart from serving as uplink ports, can also serve as service ports to provide Ethernet access. In this case, they are called the Ethernet module.
The Ethernet module supports the following features:
z Multicast service and IGMP Proxy, with up to 1000 multicast groups z PPPoA-to-PPPoE conversion
z IPoA-to-IPoE conversion
z PITP for binding between the user account and port.
z Subtending with the main control frame through the FE port or GE port
z Layer 3 forwarding that facilitates dynamic routing protocols (such as RIP and OSPF) and static routing
z Enhanced QoS and ACL functions
z QinQ, enabling point-to-point private line interconnection between different MANs z VLAN stacking, facilitating VLAN extension and wholesale private line services
2.1.5 ISU Module
Consisting of the ISU board and related software, the ISU serves as a built-in BRAS that supports user authentication based on PPPoE, VLAN binding, and VLAN+Web (forced portal and embedded portal). It also supports user accounting on the basis of the traffic volume or online duration.
2.1.6 Environment Monitor Module
The MA5600 environment monitor module consists of the power monitoring unit, power distribution monitor unit, and fan monitor unit. These units monitor the ambient temperature, humidity, smoke, smog, water logging, cabinet door sensor, and power supply.
The module is connected to the serial port MON on the SCU board. In the event of any abnormality, the module will issue an alarm to the host.
You can set the upper/lower thresholds of some environment alarms through the CLI or graphic user interface (GUI) NMS. The module shall decide whether to report alarms based on the predefined parameters. It can also adjust the fan speed according to the ambient temperature.
2.2 Hardware Architecture
This section introduces the hardware architecture of the MA5600, including the cabinet, frames and boards.
2.2.1 Cabinet
The MA5600 can be put into a 19-inch front access H66-18 or H66-22 cabinet.
I. Cabinet appearance
Figure 2-2 shows the front view of the H66 cabinet. The H66 cabinet has these features:
z The H66 cabinet has only front doors, and is only front accessible. It can be installed against the wall. The dimensions of the H66 cabinet can be:
– 600 mm x 600 mm x 1800 mm (W x D x H), or – 600 mm x 600 mm x 2200 mm (W x D x H)
Figure 2-2 Front view of the H66 cabinet
II. System layout
Considering the power supply modes and the presence of the SPL frame, the number of service frames to be held in the cabinet also varies.
Table 2-1 lists six typical layouts of the MA5600 in the H66 cabinet. For more details, refer to SmartAX MA5600 Multi-service Access Module Installation Manual.
Table 2-1 MA5600 layout in the H66 cabinet
Cabinet height Power mode Service frame SPL frame
2 Yes DC 3 No 2200 cm AC 1 Yes 1 Yes DC 2 No 1800 cm AC 1 Yes
In case there is no SPL frame, a cabinet can hold three MA5600 service frames to provide 2688 ADSL2+ subscriber lines.
In case an SPL frame is used, a cabinet can hold two MA5600 service frames to provide 1792 ADSL2+ subscriber lines.
III. Components in the cabinet
z Power supply/power distribution box
– In AC power supply mode, the MA5600 uses the GEPS4845 power module which is 3U (1U=44.45 mm) in height. Both 110 V and 220 V modules are available.
– In DC power supply mode, the MA5600 uses a power distribution box which is 2U in height, facilitating –48 V/–60 V power input.
z Modem frame
A Modem frame of 1U in height can be configured based on your actual requirements.
z MA5600 service frame
The MA5600 service frame is 10U in height (including a 1U fan frame). It constitutes the major part of the cabinet. For details on the service frame, refer to ”2.2.2 MA5600 Frame”.
The MA5600 uses fans for heat dissipation. The cool air is drawn from the bottom of the frame, passes through the service boards, and finally is driven out from the top side of the frame. The fan frame is composed of six 48 V/0.21A DC fans. For ease of maintenance, each fan can be dismounted separately. Meanwhile, each fan is equipped with a detection terminal for fan status checking.
The splitter frame is optional. It provides splitter boards to split the xDSL signal from the POTS/ISDN signal. The main control board SPMF on the splitter frame also provides a test port that connects with external tester to enable line test. z Air deflector & cabling frame
The frame (3U high) is used for air deflection and cabling.
2.2.2 MA5600 Frame
I. Hardware architecture
The MA5600 frame consists of a service frame and a splitter frame. The number of service boards and splitter boards to be configured is subject to the planned service types and traffic volumes.
The dimensions of the MA5600 service frame are: 439.00 mm x 420.00 mm x 444.50 mm (W x D x H).
The backplane of the MA5600 service frame offers GE high speed bus with 16 slots. Figure 2-3 shows the MA5600 service frame.
0 15 Line boar d Fan frame Line boar d Line boar d Line boar d Line boar d Line boar d Li ne boar d Line boar d Li ne boar d Line boar d Li ne boar d Line boar d/IS U/E IU Line boar d Mai n c ont ro l boar d Mai n c ont ro l boar d Line boar d/IS U/E IU
Figure 2-3 MA5600 service frame
The 16 slots in the service frame are numbered from 0. Among them, z Slots 7 and 8 always hold SCU boards.
z Other 14 slots can house any service board. z The ISU and EIU reside in slot 14 and/or slot 15.
Note:
The SPL frame provides 16 slots, numbered from 0 to 15. Figure 2-4 shows the board layout in the SPL frame.
S P L S P L 0 15 S P L S P L S P L S P L S P L S P L S P L S P L S P L S P L S P L S P M F
Figure 2-4 Board arrangement in the MA5600 SPL frame
The SPL frame has a control board (SPMF) and 14 splitter boards that support line capture. The SPMF provides a test port, which can connect with an external test meter to facilitate xDSL broadband line test.
II. Working principle
Figure 2-5 shows the block diagram of the MA5600 service frame. The MA5600 employs high speed backplane, enabling inter-board communication over non-blocking GE bus:
z The SCU delivers control messages to the service boards through the GE bus. z The service boards (except the ISU) report the configuration information to the
SCU through the GE bus.
z The service boards communicate with each other through the GE bus. z The ISU controls itself instead of being controlled by the SCU.
Maintenance network port Maintenance serial port Environment monitor port FE/GE port GE bus S C U S C U I S U A A D B F A D E F S H E A I S U E
ADSL2+port SHDSL port FE/GE port
E I U
GE port
Figure 2-5 Working principle of the MA5600 service frame
2.2.3 Boards, Subboards and Ports
I. Boards
Table 2-2 and Table 2-3 list all the boards residing in the service and splitter frames respectively.
Table 2-2 All boards residing in the MA5600 service frames
Name Type Function External port
SCU Super control unit The main control board for system control and IP uplink connection 1 maintenance port 1 serial port 1 environment monitor port 6 FE/GE ports
ISUA Intelligent service unit
User authentication and accounting
ISUA has two subslots: z Subslot 1 holds various
FE/GE optical subboards. z Subslot 2 holds various FE
optical subboards. z If only one subboard is
configured, it is attached to subslot 1 fixedly.
8 FE ports, or 4 FE ports + 2 GE ports
Name Type Function External port ISUE Intelligent service unit (The lower subboard is E4FB, a 4×FE electrical interface subboard)
User authentication and accounting
ISUE has two subslots: z Subslot 1 holds various
FE/GE optical subboards. z Subslot 2 holds 4xFE
subboards fixedly.
8 FE ports, or 4 FE ports + 2 GE ports
EIU Uplink port board Uplink connection. 1 GE port
ADEF 64-port ADSL2+ over POTS board
External splitter
ADSL2+ over POTS access GE bus
Line protection
64 ADSL2+ ports
ADBF 64-port ADSL2+ over ISDN board
External splitter ADSL2+ over ISDN GE bus
Line protection
64 ADSL2+ ports
SHEA 32-port SHDSL board SHDSL access GE bus
Line protection 32 SHDSL ports
Table 2-3 All boards residing in the MA5600 splitter frame
Name Type Function Port
SPMF Splitter frame main control board
Coordinate with the SCU to implement line capture control on the ADSL2+ board.
2 maintenance serial ports
2 test ports
8 subtending test ports
SPLT
64-port ADSL2+ over POTS splitter board
Splitting POTS signal from ADSL2+ signal Line capture 600 Ω impedance N+1 backup 64 ADSL2+ ports 64 LINE ports 64 POTS ports SPLQ 64-port ADSL2+ over ISDN splitter board Supports:
Splitting POTS signal with ADSL2+ signal (2B1Q) Line capture N+1 backup 64 ADSL2+ ports 64 LINE ports 64 ISDN ports II. Subboards
Table 2-4 Subboards attached to the MA5600’s SCU board
Name Type Position
H531O4GS 4-port GE optical subboard H531O2GS 2-port GE optical subboard H531E2GA 2-port GE/FE electrical subboard
H561E4GFA 4-port GE/FE electrical subboard
H561O4FM 4-port FE optical subboard
Note: The MA5600 optical port employs the SFP swappable module. Various reaches are supported through SFP module replacement:
z GE single-mode optical module: 10 km
z GE multi-mode optical module: 500 m
z FE single-mode optical module: 15 km
z FE multi-mode optical module: 2 km
2.3 Software Architecture
The MA5600 software consists of the board software and host software. In Figure 2-6, the part enclosed by the dotted line depicts the software architecture of the MA5600.
MA5600 software architecture Serial terminal Telnet Host software Board software 1 Board software 2 Board software N ...
Communication control bus Serial port connection NMS Inband/ outband Inband/outbant
I. Board software
The MA5600 board software runs on the service boards for the following purposes: z Service management
z Data management z Alarm management z Driving and diagnosis
II. Host software
The MA5600 host software runs on the main control board. The software architecture is based on the TCP/IP model. This architecture covers configuration management, system service, routing protocol, TCP/IP protocol stack, VLAN protocol, and bottom driver. It processes network layer protocols, data link layer protocols and messages. Figure 2-7 shows the MA5600 host software architecture.
TCP/UDP
IP forwarding engine (unicast/multicast forwarding)
Fast forwarding QoS
Routing strategy management System service Co nfi gurati on mana gem en t CLI SNMP Device management TFTP FTP TELNET … STP/RSTP Xmodem IGMP Proxy 802.1x Bottom driver TCP/UDP
IP forwarding engine (unicast/multicast forwarding)
Fast forwarding QoS
Routing strategy management System service Co nfi gurati on mana gem en t CLI SNMP Device management TFTP FTP TELNET … STP/RSTP Xmodem IGMP Proxy 802.1x Bottom driver
Figure 2-7 Host software architecture of the MA5600
The MA5600 functional modules and their functions are summarized as follows: z Configuration management module
This module is composed of the CLI terminal and NMS. z System service module
Services available include configuration, alarm generation, log, traffic statistics collection and maintenance management.
z Routing and TCP/IP protocol stack module
This module processes network layer protocols and data link layer protocols. z Bottom driver module
This module is responsible for device management, loading & backup, operation system, virtual operating system, bottom layer communication and
Chapter 3 Service Functions
This chapter introduces service functions of the MA5600, including: z Broadband Access Services
z VLAN Services z Multicast Services
z MAC Address Management z Built-in ISU
z Routing Management z ARP and ARP Proxy z STP/RSTP
z QoS
z Terminal Management z Environment Monitoring
3.1 Broadband Access Services
3.1.1 ADSL2+ Service
ADSL2+ is a new generation ADSL technology. Being fully compatible with ADSL, ADSL2+ has the following enhanced features:
I. New operation modes
ADSL has three operation modes:
z ADSL Annex A — All Digital Mode ADSL with Improved Spectral Compatibility with ADSL over POTS. It provides the POTS and ADSL services at the same time over the same copper pairs.
z ADSL Annex B — All Digital Mode ADSL with Improved Spectral Compatibility with ADSL over ISDN. It provides the ISDN and ADSL services at the same time over the same copper pairs.
z ADSL Annex C — It provides ADSL in TCM-ISDN crosstalk environment. It is mainly applied in Japan.
Apart from the above three modes, the following modes are added to ADSL2+: z Annex I — Annex A without underlying POTS service. In this mode, the ADSL2
upstream channel uses a frequency spectrum of 3–138 KHz, and supports 31 sub-carriers. Accordingly, the upstream bandwidth is increased to over 1 Mbit/s.
z Annex J — Annex B without underlying ISDN service. In this mode, the upstream uses a frequency spectrum of 3–276 KHz and supports 64 sub-carriers. Accordingly, the maximum upstream bandwidth is increased to 2.3 Mbit/s.
II. Improved transmission rate
Compared with ADSL, ADSL2+ supports much higher rate: up to 24 Mbit/s downstream rate in short-reach transmissions. This is done though the following enhancements: z Improved frame structure
z Optimized R-S coding z Wider frequency range z More subcarriers (up to 512)
When ADSL2 Annex J is adopted, the upstream rate can reach 2.3 Mbit/s.
III. Longer transmission reach
Compared with the 5 km reach of ADSL, ADSL2+ supports a transmission reach of 6.5 km at 192/128 kbit/s.
IV. Less power consumption
ADSL2+ supports power management, aiming to reduce overall power consumption. The following measures are taken for this purpose:
z It reduces the power consumption while guaranteeing reliable operation by eliminating excess SNR margin and cutting back the transmit power.
z The newly added L2 low power mode can reduce the transmit power by maintaining just necessary management messages and synchronous signals when there is no subscriber data traffic. However, the power mode will exit L2 mode to a normal mode when there is subscriber data traffic. Power consumption in L2 mode is about 30% of that in normal power mode.
z In ADSL2+, the CO and CPE both support power cutback ranging from 0 dB to 40 dB. This can effectively decrease transmit power in normal operations.
V. Reliable operation and good frequency spectrum interoperability
ADSL2+ is characterized by reliable operation and excellent frequency spectrum interoperability:
z The tone ordering and pilot tone location is determined by the receiver based on the channel analysis in order to reflect the real channel conditions and to select the best tone as the pilot tone. This improves reliability of the ADSL connection. z In the training, the tone blackout enables the receiver to test the Radio Frequency
each tone through the CO-MIB. This helps to avoid RFI and reduce crosstalk from other wire pairs.
z ADSL2+ supports dynamic rate adaptation. Enhanced bit swap and seamless rate adaptation during show time can improve the tolerance to the line parameter changing.
z The short training procedure enables fast recovery and resynchronization from errors.
VI. Line diagnosis
ADSL2+ supports dual-end loop test, enabling training between the CO and the CPE. The following line parameters can be obtained through a line test:
z Line characteristics
z Quiet line noise Power Spectral Density (PSD) z SNR of a subcarrier
z SNR gap of a subcarrier z Bearable bits of a subcarrier z Attainable data rate
VII. Better interconnectivity
ADSL2+ divides the ADSL transceiver into several sublayers:
z Transport Protocol Specific Transmission Convergence (TPS-TC) z Physical Media Specific Transmission Convergence (PMS-TC) z Physical Medium Dependent (PMD)
z Management Protocol Specific Transmission Convergence (MPS-TC)
It encapsulates each sublayer and defines messages between these sublayers. This aids in interoperation between different vendors’ devices.
3.1.2 SHDSL Service
SHDSL provides high speed symmetric data service over one or two twisted pairs. In SHDSL access application, the transmit rate ranges from 192 kbit/s to 2312 kbit/s. SHDSL can automatically adjust the transmission rate at the step of 64 kbit/s based on distance, line status and noise level.
Features of SHDSL module are as follows:
z Conforming to ITU-T G.991.2 Annex A and Annex B.
z Adopting Trellis Coded Pulse Amplitude Modulation (TC-PAM) for modulation/modulation.
z Delivering symmetric data rate at 192–2312 kbit/s.
z Adjusting the transmission rate at the step of 64 kbit/s based on the line conditions at the time of initialization.
z The STU-R derives power supply from an external power unit. The ESH board communicates with the external power unit and performs remote monitoring on the power supply.
z Querying and configures SHDSL line parameters, including upstream and downstream transmission rate, NRS margin, output power, and line attenuation. z Supporting online loading of programmable units and board software.
z Supporting remote maintenance and software upgrade. z Supporting output of line alarm messages.
z Supporting online upgrading and remote maintenance of firmware and software. z Supporting board alarms and line alarms, including state alarms related to lines
and interfaces, as well as fault alarms related to the remote power supply of subscriber interfaces.
3.1.3 LAN Service
LAN service is a popular data communication service at present. It allows data burst and is delay insensitive. It is mainly applied to 100BASE-TX Ethernet access based on UTP-5 for a reach smaller than 100 m.
The MA5600 is capable of transparent bridging for LAN access service. The MA5600 can provide broadband private line access for medium and small enterprises that are unable to establish their own private networks, or are unable to afford digital data networks (DDNs), allowing interconnection between the headquarters and the branches, and between the enterprise and the Internet with guaranteed QoS such as certain bandwidth and delay. In this way, these enterprises can easily establish their own VPNs over the public network.
3.2 VLAN Services
VLAN technology classifies devices on a number of different local area networks (LANs) based on logical instead of physical connections. This technology makes it possible to divide a physical LAN into different broadcast domains (known as VLANs) logically.
3.2.1 Standard VLAN
A standard VLAN means a common VLAN. The ports in a standard VLAN are interconnected and all ports are logically equal to each other. IEEE issued 802.1q standard draft on LAN implementation in 1999.
The VLAN technology makes it possible to divide a physical LAN into different broadcast domains (known as VLANs) logically. Each VLAN contains a group of work stations with the same requirements, similar as a LAN in the physical sense. Since a
network segments. The broadcast and unicast flows of one VLAN will not be forwarded to other VLANs. This help to ease flow control, simplify network management, protect carrier investment, and improve network security.
3.2.2 MUX VLAN
A MUX VLAN is an application of the VLAN technology. Its implementation is the same as that of Standard VLAN. However, compared with a Standard VLAN, a MUX VLAN includes one or more upstream ports and an access port. Upstream ports are standardized, while the access port is a virtual service port for user access.
A MUX VLAN adopts a VLAN to identify an access connection.
3.2.3 Smart VLAN
A Smart VLAN is also an application of the VLAN technology. Its functions are the same as those of Standard VLAN. However, compared with a Standard VLAN, a Smart VLAN includes one upstream interface and multiple virtual service ports for user access, but these virtual service ports are isolated each other.
Smart VLAN has the following features:
z Two types of ports: upstream port and downstream port
z The downstream ports are isolated from each other on the physical layer; the downstream port can communicate with the upstream port; the upstream ports can communicate with each other; the principle for interworking between upstream ports in Smart VLAN is the same as that in common VLAN.
z Broadcast domains are isolated at two layers (physical layer and link layer), thereby restricting the broadcast domain and broadcast packets to ensure the user privacy and network security.
The MA5600 supports 255 Smart VLANs.
In real application, after you allocate multiple downstream ports and one or more upstream ports to a Smart VLAN, the system will automatically create internal mapping between the upstream port(s) and downstream ports. In this way MUX VLAN helps to ease the manual configuration isolate user packets at L2. Such strategy simplifies the configuration and saves VLAN and IP address resources.
A Smart VLAN does not affect implementation of a common VLAN.
3.2.4 Super VLAN
Super VLAN and Sub VLAN are supported in VLAN aggregation. A Sub VLAN is a MUX VLAN, Smart VLAN, or Standard VLAN, but cannot work in QinQ or Stacking
mode. A Sub VLAN belongs to a Super VLAN, and a Super VLAN can include a group of Sub VLANs.
A Super VLAN corresponds to a route interface at L3. All Sub VLANs in the Super VLAN share the route interface. This helps to save IP address resources.
A Super VLAN is in a physical network, using VLANs to separate it from broadcast domains. Host IP addresses are allocated within a network segment, using a default gateway.
3.2.5 QinQ VLAN
802.1q in 802.1q (QinQ) VLAN enables transmission of VLANs and services of a private network to the peer end transparently. It is mainly used for leased line services. A QinQ VLAN ensures that an enterprise’s internal VLAN Tags can reach to a remote network through a simple layer 2 tunnel. The following introduces the implementation of a QinQ VLAN.
After receiving a packet with private VLAN tag, a DSLAM device will assign a public VLAN ID to the packet and then send it to the upstream network. The packet is transmitted in the metropolitan backbone network based on its public VLAN ID. When it reaches a DSLAM device on the other end of the backbone network, its public VLAN tag will be extracted and restore the original user packet. Then, the packet will be sent to the CPE.
In summary, the packet delivered in the backbone network has two layers of 802.1q tags: a public VLAN tag and a private one. In this way, transparent delivery of private VLANs is realized and public VLAN ID resources are greatly saved.
3.2.6 VLAN Stacking
VLAN stacking is adopted to realize VLAN extension and private line wholesale service.
When multiple ISPs exist in a L2 metropolitan network, in user access, the user is identified by its external VLAN ID in the VLAN stacking. The external VLAN ID tells to which ISP the user belongs. When a user port is connected to a DSLAM device, the packets from the port are labeled with L2 Tags by the DSLAM device.
The implementation of VLAN stacking is as follows: z VLAN extension
A BRAS is need for VLAN extension and user identification. The system assigns an internal tag (Customer VLAN) to each port where VLAN stacking is enabled.
respectively. The packets from these ports are forwarded in the network based on their external VLAN IDs. After having received the packets, the BRAS will extract the external VLAN tag and identifies the user by the internal VLAN tag.
z Private line wholesale service
When VLAN stacking is adopted to realize private line wholesale service, it is required that the upper layer network works in L2 mode, and packets are forwarded directly based on VLANs and MAC addresses.
3.3 Multicast Services
Multicast refers to a process of transmitting packets of data from one source to many destinations. The key of multicast technology is to carry out packet duplication as near as the receiver.
Multicast helps to:
z Reduce load on the server, so that the server need not handle request on a per user basis.
z Save network bandwidth, which lowers the requirement on the network device. z Adapt to various user quantities, so that increase of users will not impose pressure
on the network.
The following example shows the implementation of multicast. Assume a source host sends a datagram. The destination in the datagram is the multicast address. All hosts in the multicast group (namely hosts with the destination multicast address) group can receive a copy of the datagram. But other hosts in the network cannot receive the packet. A multicast group is identified by D-class IP address (from 224.0.0.0 to 239.255.255.255).
The MA5600 supports IGMP Proxy and managed multicast.
3.3.1 IGMP Proxy
The MA5600 supports the IGMP proxy function. With the IGMP proxy function, the multicast router, rather than the MA5600, performs the routing.
From the perspective of a multicast user, the MA5600 is a multicast router implementing the router’s functions defined in the IGMP. It receives the requests from its downlink users for joining or leaving a multicast group. It also queries at regular intervals whether a downstream port has multicast group users. By doing so, the MA5600 obtains multicast group membership information on the downstream ports. On the other hand, from the perspective of a multicast router, the MA5600 is a multicast host which sends IGMP requests to the multicast router for joining or leaving a
designated multicast group. The multicast router does not feel the existence of real user hosts.
The MA5600 controls the multicast group demanded by the user through the CLI or NMS. Then it forwards the multicast traffic from the upstream port to the downstream port based on its group membership information.
The uplink and the downstream ports may not belong to the same VLAN. That is, inter-VLAN multicast forward is supported. However, an upstream port cannot forward the multicast data received from its downstream ports, or forward multicast data to other upstream ports.
3.3.2 Managed Multicast
The MA5600 provides managed multicast based on standardized multicast protocols. Managed multicast means that the multicast message is under control. It involves: z Program management
This prevents illegal multicast stream from being forwarded. z User management
This prevents illegal users from watching video programs, and restricts the number of programs a user can watch, fast-leave, and so on.
z Authority management
Different multicast users have different authorities to watch and preview programs. This function enables an operable BTV.
3.4 MAC Address Management
The MA5600 maintains an address list in its main control board and service boards respectively for packet forwarding. It contains the MA5600 port numbers, and the MAC addresses of other devices connected to the MA5600.
The MA5600 is capable of learning new addresses. If the source address of a received packet does not exist in the address list, the MA5600 can add the source address and the port ID of the received packet to the address list as a new entry. The Administrator can configure the address list as required. The added or modified item can be either a static one or a dynamic one.
The MA5600 also provides address aging function. The MA5600 will delete the associated address items of the equipment which has not sent any packet for a certain period of time. The address aging function only applies to dynamic address entries. The addresses are shared by all VLANs.
3.5 Built-in ISU
The MA5600 supports the remote broadband access server functions through its built-in Intelligent Service Unit (ISU). The ISU enhances the MA5600’ performances in respect of user management, service control, as well as authentication & accounting. The built-in ISU has these functions:
z Supporting both VLAN user access and PPPoE user access.
z Providing multiple authentication means for fixed network users and wireless network users. (For instance, port binding authentication, Web authentication, and fast Web authentication.)
z Supporting leveled user control based on domain name and user account. z Supporting high speed forwarding, switching and routing.
z Managing the user and the equipment.
z Supporting accounting based on traffic or duration.
z Supporting accounting using RADIUS. The ISU can store 50,000 bills in a local memory; and it can output the accounting data to an AAA server anytime.
z Supporting both static and dynamic IP address allocation and management. z Managing multicast user groups using IGMP.
3.6 Routing Management
In the MA5600, you can either configure a static route manually, or configure a dynamic routing protocol for the system to detect a dynamic route. The static route and the dynamic route are managed uniformly by the MA5600. The static routes and the dynamic routes can be shared.
I. Static route
A static route is a special kind of route that is configured manually by the administrator. By configuring a static route, an interworking network will be created. However, when a network fault occurs, the static route cannot change automatically, and the administrator has to reconfigure it.
II. RIP
Routing Information Protocol (RIP) is a kind of protocol based on the V-D algorithm. It exchanges routing information through the User Datagram Protocol (UDP) datagram, and sends the routing updates every 30 seconds. If the router does not receive an update from the opposite end within 180 seconds, all updates from this router will be labeled unreachable. Moreover, the updates will be deleted if this router still does not receive any update within another 120 seconds.
RIP uses Hop Count to measure the distance to the sink machine, which is called Routing Metric. With RIP, the hop count from the equipment to the network connected directly with it is 0 (defined as 1 in some protocol), the distance from the equipment to a network reachable is 1 hop, and the rest may be deduced by analogy. To restrict the convergence time, the Metric is defined as an integral number in the range of 0–15 in RIP. The hop count will be taken as infinite if it is greater than or equal to 16.
To avoid route loopback and enhance the performance, RIP supports the split-horizon algorithm. The trigger update is adopted for the change of the routing information. Moreover, this protocol allows the redistribution of routes obtained by other routing protocols.
The MA5600 supports two versions of RIP (that is, RIP I and RIP II) at the same time. RIP II supports authentication in both clear text and MD5 cipher text and the length-variable subnet mask.
III. OSPF
In the IP network, Open Shortest Path First (OSPF) can dynamically detect and transmit routes by collecting and transmitting the link state of the autonomous system. At present, the second version of OSPF is used. It has the following characteristics: z Wide application range
OSPF supports networks of various scales, with a maximum of several hundreds of routers supported.
z Fast convergence
If the topology of the network changes, OSPF can transmit update packets immediately so that the change can be synchronized with the autonomous system.
z No self-loop
OSPF calculates routes based on the algorithm of shortest path tree first through the collected link state. Therefore, the algorithm itself can ensure that no self-loop route is generated.
z Subnet mask
OSPF carries the mask information about the network section when describing the route. Therefore, the OSPF protocol gets free from the restriction of the natural mask and provides sound support for Variable-Length Subnet Mask (VLSM). z Area division
OSPF allows the network of the autonomous system to be divided into various areas for management. In this way, the inter-area transmitted routing information is further abstracted, thus reducing the occupied network bandwidth.
OSPF supports multiple equivalent routes to the same destination. z Route hierarchy
OSPF uses 4 types of routes. Based on the sequence of preferences, these routes are: intra-area route, inter-area route, the first category of external route and the second category of external route respectively.
z Supporting authentication
It supports the interface-based packet authentication to ensure the security of the route calculation.
z Multicast transmission
OSPF can transmit protocol packets by the multicast address at the link layer capable of multicast transmission. In this way, the broadcast function is realized and the interference to other network equipment is reduced to the minimum degree.
3.7 ARP and ARP Proxy
I. ARP
ARP realizes dynamic mapping between an IP address and an MAC address, allowing the host to find the physical address of a target on the same network given the target's IP Address.
II. ARP Proxy
When an L3 broadcast domain is isolated at L2 by network devices, ARP Proxy is used to enable normal communication between two hosts isolated from each other at L2, the network device need support ARP Proxy.
ARP Proxy is used in VLAN aggregation applications such as a Smart VLAN where the users in the same VLAN are isolated. Here ARP Proxy is only concerned with such application as users in the same VLAN are isolated from each other by network devices.
Respond PC1 with MAC port1 ARP-PROXY ARP-request ARP-reply port2 PC1 PC1 Respond PC2 with MAC
Figure 3-1 ARP Proxy implementation
As shown in Figure 3-1, PC1 and PC2 both belong to VLAN1. They are isolated from each other at L2. When PC1 needs to communicate with PC2, it will send an ARP request after having found that PC2 is located in the same subnet as PC1.
When the MA5600 receives the ARP request, it firstly searches the destination IP address carried by the ARP request in the ARP table. If the MA5600 finds the corresponding entry, it will respond PC1 with VLAN1’s MAC address, thereby completing the proxy function.
If the MA5600 cannot find the corresponding entry, it will replace the source MAC address contained in the request with VLAN1’s MAC address, and broadcast the request in VLAN1. Meanwhile, the MA5600 will also add the information it learnt from the ARP request to the dynamic ARP table.
After that, when the MA5600 receives PC2’s ARP response, whose destination MAC address is VLAN1’s MAC address, its ARP module will search the MAC address in the ARP table. If the MA5600 finds in the table the MAC address entry corresponding to VLAN1, it will then respond PC1 with this MAC address.
3.8 STP/RSTP
Spanning Tree Protocol (STP) is applicable to loop network. Targeted at preventing infinite packet generation and cycling within the loop network, STP uses a certain algorithm to block redundant routes and modify the loop network into loopless tree network.
STP functions as follows: It determines the network topology through exchanging of a specific packet between devices. This packet is referred to as ‘configuration message’ in IEEE 802.1D. The ‘configuration message’ contains information necessary for the spanning tree calculation.