Multicast for Generic Ethernet Access products

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Multicast for Generic

Ethernet Access

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Product Description

Contents

Page

Document Description

4

Document Control

4

Notice

4

1

Introduction & Background

5

2

Multicast overview

5

3

Multicast Specification

5

3.1

Multicast at the L2S

5

3.2

Channel management

6

3.3

GEA Data service relationship with End User Multicast access.

6

3.4

End User experience and traffic management

6

4

Multicast Network Architecture

7

5

Network interfaces for GEA-FTTx multicast

8

5.1

Multicast VLAN

8

5.1.1

GEA-Cablelink

8

5.1.2

Multicast VLAN capacity

8

5.1.3

MC VLAN tag

8

5.1.4

Internet Group Management Protocol (IGMP)

8

5.1.4.1

Version

8

5.1.4.2

IP versions

8

5.1.4.3

IGMP message rate limiter

8

5.1.4.4

IGMP encapsulation

9

5.1.4.5

IGMP Proxying

9

5.1.4.6

IGMP forking

9

5.1.5

VLAN use

9

5.1.6

Concurrent Channels per End User limiter

9

5.2

Per GEA-FTTx data service configuration

9

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Product Description

5.2.2

Multicast Channel Access

9

5.2.3

Configuration

10

6

Multicast traffic handling

10

6.1

Downstream QoS

10

6.2

GEA-FTTC

10

6.3

GEA-FTTP

10

6.4

Prioritisation rate

10

6.5

Upstream QoS

10

6.6

Multicast IP addresses

10

7

Known considerations

10

8

Equivalence Management Platform (EMP)

11

8.1

L2C Functionality

11

8.2

T2R Functionality

11

8.3

Additional EMP stories

12

9

Commercial

12

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Product Description

Document Description

This document provides an overview for the Openreach Multicast capability for the Generic Ethernet Access product. It is applicable on both Fibre to the Cabinet (GEA-FTTC) and Fibre to the Premises (GEA-FTTP).

This document also incorporates the draft network interface specifications for GEA-Multicast.

Document Control

Issue No: Date: Author / Editor: Details of Change:

Issue 3.1 1st April 2011 Brett Smithers Updates including IGMP Proxying Source Addresses and ordering Multicast and Cablelink DUNS ID. Issue 3.0 14th Feb 2011 John Greenstreet Updates including revision to VLAN

range and method of allocation. Issue 2.0 24th Sep 2010 John Greenstreet Updated

Issue 1.1 10th May 2010 John Greenstreet IGMPv3 to be supported Issue 1.0 29th March 2010 John Greenstreet First issue

Notice

The information within this document is provided for information purposes only. This is a living document and will be subject to update and change. However, BT maintains that all reasonable care and skill has been used in the compilation of this publication and BT shall not be under any liability for loss or damage (including consequential loss) whatsoever or howsoever arising as a result of the use of this publication by the reader, the reader’s servants, agents or any third party. In the event of a discrepancy between the content of this document and the contract terms and conditions, the contract terms and conditions shall prevail.

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Product Description

1 Introduction & Background

Multicasting at its simplest is the capability to transmit one stream of data and that data stream only gets split into individual streams nearer to the End User’s site. Examples of use include broadcast TV, streaming of data such as race results or share prices or for pre-downloads such as media/software/firmware updates.

Multicasting avoids having to send multiple individual streams through most of the network. This has the benefit of reducing the required bandwidth in a CP’s network enabling a reduction in the associated backhaul cost. This will become more relevant going forward as data volume

increases and where multicast can help to restrict network development costs.

Openreach received interest from CPs for the development of a Multicast feature to be developed for the GEA products. This document outlines the Multicast capabilities following feedback from CPs in 2010 regarding the most appropriate technical solution and to determine a workable commercial model.

2 Multicast overview

GEA Multicast is a dynamic point to multipoint network layer enabling users to subscribe to IP data streams served by their provider. The CP provider requires a Multicast VLAN, which is a GEA product option, to benefit from this facility.

The key features are:

 Multicast is a feature of the GEA Data products. This service will be provided alongside GEA-FTTP Data or GEA-FTTC Data services, with service being delivered over the same End User Ethernet data port as the Data service.

 Multicast would be made available within the GEA footprint and handover locations.

 GEA Cablelink is required to be in place with full backhaul connectivity to your network

 Openreach would provide multicast VLAN at each enabled L2S that will serve both FTTC and FTTP fed from that L2S.

 Your GEA-FTTP Data and GEA-FTTC Data services will automatically be enabled for multicast where you have ordered a Multicast VLAN on the same L2S.

 The standard lead time for the provision of a Multicast VLAN is 20 working days.

 The Multicast VLANs will be provided in fixed 5Mbit/s increments starting from 0Mbit/s up to 200Mbit/s then in 10Mbit/s increments with an upper limit of 300Mbit/s.

 A maximum of four Multicast VLANs (i.e. 4 CPs) would initially be permitted per L2S.

 A minimum term of 12 months would apply during which there would only be upward upgrades. Modifications may be restricted to one modification a month.

3 Multicast Specification

3.1 Multicast at the L2S

 You can obtain capacity at a NGA L2S enabled for Multicast

 This capacity is available for you to transport data to your End Users on all PONs and DSLAMs on that L2S. You need not be aware of individual PONs or DSLAMs.

 Multicast will be transported through the Openreach network with a higher priority than GEA Data.

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Product Description

 At the line egress port, it will be possible to prioritise selected GEA Data traffic above MC by setting C-VLAN 802.1p of GEA Data traffic to 4.

 Capacity is presented to you as a Multicast VLAN.

 Only one GEA Cablelink is required (and permitted) to carry Multicast traffic per L2S.The multicast VLAN ID at an available L2S will be system generated and will be allocated sequentially (this ensures that

duplicate IDs do not occur)

. The VLAN ID will be in the range 3001 to 3070.

 You should give careful consideration regarding any selection of a GEA Cablelink that a Multicast VLAN is applied to as it cannot be ‘shifted’ to another GEA Cablelink at a later date, nor can the VLAN ID be changed at a later date. This is particularly important if multiple group entities use the same GEA Cablelink.

3.2 Channel management

 Openreach will expect you to limit the channels (group addresses) within a Multicast VLAN that each End User is allowed to access. Openreach will remain unaware of this.

 Openreach will expect you to control the bandwidth allocations to each channel within your overall Multicast VLAN capacity. Openreach will remain unaware of this.

 Openreach will police the Multicast VLAN to the bandwidth ordered by you. You will be unable to use bandwidth beyond the Multicast bandwidth rented.

3.3 GEA Data service relationship with End User Multicast access.

 All of your GEA-FTTP and GEA-FTTC Data services (User connections) on the L2S and DSLAM will be automatically enabled for multicast where you have ordered a Multicast VLAN at that L2S.

 Multicast traffic will be delivered to the End User via the same Ethernet port on the ONT or Active NTE as the GEA Data service.

 Access cannot be given to a Multicast VLAN owned by a different CP.

3.4 End User experience and traffic management

 You will need to ensure that the total of multicast traffic delivered at the End User’s premises on the GEA Data service port, plus any requirement for other traffic to the EU, does not exceed the capacity of the port and additionally for FTTC the line rate for FTTC.

 Multicast will be transported through the Openreach network with i. a higher priority than GEA Data

ii. a lower priority than FVA.

 At the line egress port, it will be possible to prioritise selected GEA Data traffic above MC by setting C-VLAN 802.1p to 4.

 FVA will have a higher priority than either MC or GEA Data

 IGMP Fast Channel Change will be supported.

 You should be aware that to support both unicast and multicast, there is a need to support IPoE and PPPoE simultaneous (dual stack) on the same WAN interface on the router / home gateway. This may not be supported by a number of routers, but is certainly possible.

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Product Description

4 Multicast Network Architecture

Figure 1 Multicasting network architecture

NGA supports proxy reporting. It means that CP equipment does not see, or need to process, every IGMP report from all End Users; only the first join and last leave per channel is seen at the CP handover port. This is illustrated in Figure 2 below.

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Product Description

5 Network interfaces for GEA-FTTx multicast

The network interface information for the GEA-Multicast described below represents the current view that Openreach is able to provide and reflects the current specifications from our technology suppliers which remain subject to full commitment and any further development.

5.1 Multicast VLAN

A single Multicast VLAN (MC VLAN) will be supported for a CP on each Layer 2 switch (L2S). There will be a maximum of four MC VLANs per L2S.

5.1.1 GEA-Cablelink

You will specify which GEA-Cablelink is to be used to support the MC VLAN.

5.1.2 Multicast VLAN capacity

You can specify a value from a range of bandwidths for the MC VLAN. The exact values will be 0Mbit/s to 200Mbits in 5Mbit/s increments, then in 10Mbit/s increments to a maximum of

300Mbit/s per CP.

The 0Mbit/s bandwidth has been established to allow advance multicast setup and configuration, allowing you more control for a known future date of multicast activation should you require it. You will be able to change the bandwidth via a Modify order. A modify order is only upwards for the first 12 months. There is no cease capability during this time. Subsequently, you will be able to modify multicast down to 0Mbit/s after 12 months.

Openreach will police the MC VLAN to the bandwidth requested. In the event of excess traffic being supplied from you, packets would be dropped at random. It is therefore important that you ensure sufficient bandwidth for the services you wish to offer and that transmitted multicast traffic is shaped i.e. without burst.

5.1.3 MC VLAN tag

The MC VLAN will:

a. Be provided with a single tag (IEEE 802.1Q) b. Have a tag ID within the range 3001 to 3070.

5.1.4

Internet Group Management Protocol (IGMP)

5.1.4.1 Version

IGMP proxy functions sit between the CP and User network interfaces. GEA Multicast supports IGMPv3 and IGMPv2 at the User interface. At the CP interface, only IGMPv3 should be configured on connecting network devices owing to the fact that IGMPv2 is not be supported on certain L2S types used by Openreach.

GEA Multicast does not support IGMPv3 SSM (Source Specific Multicast), this is because the forwarding function in the L2S / DSLAM operates at layer 2 as described in Broadband Forum TR-101 & TR-156.

5.1.4.2 IP versions

 IP v4 is supported.

 IP v6 is likely to be supported in future, but is not currently supported.

5.1.4.3 IGMP message rate limiter

To protect NGA resources, an IGMP limiter is applied to the End User Ethernet data port. This applies only to IGMPoE packets destined for GEA Multicast. A rate not exceeding 8 IGMP reports per second is supported per End User data port. Beyond this rate, IGMP reports may be delayed or ignored by the DSLAM or ONT. Note that since multicast clients tend to use Robustness = 2

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Product Description

as recommended by RFC3376, there are typically 2 messages per join and 2 per leave. Thus, the equivalent channel change rate is 2 channels per second per End User Port.

5.1.4.4 IGMP encapsulation

IGMP messages to/from GEA-Multicast are to be encapsulated as IP over Ethernet (IPoE). IGMP messages as part of multicast applications running over GEA Data must be sent over the PPPoE connection layer and will be passed to the Openreach CP on the normal data VLAN without being processed/acted on by Openreach.

Note – if a CP uses Dynamic Host Configuration Protocol (DHCP) rather than PPPoE, the CP will

need to ensure that any IGMP messages meant for the data VLAN will need to be: a) Not IGMP over Ethernet, and

b) Sent with a VLAN tag other than 0.

5.1.4.5 IGMP Proxying

Openreach will act as an IGMP proxy.

IGMP join requests will only be sent to the CP when a request has been received for a channel which is not currently being received from the CP at the multicast point.

IGMP leave requests will only be sent to the CP when a channel is no longer being requested by any GEA Data services served by multicast point.

IGMP joins/leaves will not identify individual GEA-FTTx Data services.

The source IP address of query messages to the User interface will either have a source IP address of 0.0.0.0, or 172.17.17.17. The source IP addresses have been reviewed and Openreach will continue to use both. These are both valid source IP addresses for Multicast.

5.1.4.6 IGMP forking

Openreach will not provide forking (copying) of the IGMP messages, so that: a) IGMP messages will be presented to the CP on the Multicast VLAN only.

b) Openreach will not provide a parallel feed of IGMP messages on the normal data VLAN.

5.1.5 VLAN use

IGMP messages can be sent from the CPE to the Openreach Active NTE either: a) With no VLAN tagging; or

b) With VLAN tagging but only where VLAN tag 0 is used. If other tag values are used, the IGMP message will not be processed by Openreach and will be passed to the CP on the normal data VLAN.

5.1.6 Concurrent Channels per End User limiter

The maximum number of groups an End User is permitted be a member at any time is restricted to 16. This is to protect NGA resources from misuse or malfunctioning CPE.

5.2 Per GEA-FTTx data service configuration

5.2.1 Multicast Access

Openreach will enable, or disable, your GEA Data services for GEA-Multicast on a per L2S basis.

5.2.2 Multicast Channel Access

Openreach will not manage any restriction of access to your multicast streams (content) that can be accessed by any GEA Data service. All restrictions are your responsibility i.e. that of the CP.

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Product Description

5.2.3 Configuration

Openreach will not manage configuration of any multicast parameters for any individual GEA-FTTx Data service.

6 Multicast traffic handling

6.1 Downstream QoS

Any .1p markings on multicast traffic will be ignored by Openreach. Instead Openreach will re-mark downstream multicast traffic with 802.1p priority 3.

6.2 GEA-FTTC

On GEA-FTTC, the data traffic and the multicast traffic will share the available downstream bandwidth. It is your responsibility to manage the relative amounts of multicast and data traffic within the available bandwidth to the End User to ensure that high priority data traffic does not squeeze out multicast traffic, or vice versa.

6.3 GEA-FTTP

On GEA–FTTP the product specification is that sum of the multicast and data traffic shall not exceed the downstream PIR rate bought e.g. 40Mbit/s / 100Mbit/s. However, in the initial implementation multicast traffic is additional to the data traffic to the ONT, but this may be changed at a later date.

6.4 Prioritisation rate

On both GEA-FTTC and GEA-FTTP, multicast traffic does not impact the prioritisation rate for the Data service (though note that it does reduce the share of the line rate available to deliver GEA-FTTC).

6.5 Upstream QoS

On GEA-FTTC, the Active NTE (modem) is not aware of the IGMP messages. You are therefore advised to make use of upstream QoS markings (VLAN0) to ensure that IGMP messages are transmitted from the Active NTE (modem) to the DSLAM as quickly as possible.

6.6 Multicast IP addresses

Openreach will support IP multicast group addresses in the range 224.0.1.0 to 239.255.255.255. The range 224.0.0.0/24 reserved range will not be accepted in accordance to IANA.

7 Known considerations

Openreach will only provide a Multicast VLAN to a GEA-Cablelink where the DUNS ID for Multicast VLAN order and the DUNS ID for the GEA-Cablelink order are the same.

FTTC only offers one data service and as such will only offer one Multicast facility to that CP. Technical limitations of the Active NTE (ONT) for FTTP will result in only one Multicast facility being available during trials/pilot. This will be available to the data service on port 1.

Huawei specific: The 8240 r2 ONT will only support one Multicast service across all 4 ports. It is

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Product Description

ECI specific: The ECI ONT will be able to support 4 Multicast services (either from the same or

different CPs), one for each port.

8 Equivalence Management Platform (EMP)

Openreach anticipates that the service provision and assurance processes for both the technical trial and any wider market deployment would be supported by an Equivalence Management Platform (EMP) interface consistent with other Openreach NGA products.

.

8.1 L2C Functionality

You will be able to order Multicast on a L2S by using the portal, following a similar process as that for ordering GEA-Cablelinks. As part of the order you will have to specify the GEA-Cablelink ID where the Multicast VLAN is to be provided. The VLAN ID will be from the range of 3001-3070, will be system generated and allocated sequentially. It is not possible to change the VLAN ID once allocated.

Only one VLAN is permitted per CP per L2S, despite the fact that multiple GEA-Cablelinks may be used to provide the bandwidth required to support all GEA Data users belonging to the CP. The Multicast VLAN will reach all your users, even if their GEA Data is supported by another GEA-Cablelink.

When you become Multicast enabled, all your end users are automatically enabled too. As a Multicast enabled CP, all your subsequent GEA Data provisions will automatically enable the EU for Multicast.

The Multicast VLAN is sized and charged according the your requirements and range from 0Mbit/s to 300Mbit/s. Increments are in 5Mb/s up to 200Mb/s then 10Mb/s steps up to 300Mb/s. The 0Mbit/s Multicast VLAN allows you (if you require) to prepare end users for Multicast

enablement prior to you having to pay for Multicast VLAN rental.

Reference ID Functionality Description

ORC2M-6183

This provides the main L2C capability for Multicast. It allows you (CPs) to order/modify/cease Multicast VLANs and implements the network

functionality that delivers Multicast traffic to FTTC&FTTP customers with the appropriate priority fit for video traffic. It also enables Openreach to bill for Multicast services.

8.2 T2R Functionality

It is expected in the first instance that you will have to ascertain that problems with the service do not relate to a problem with the underlying GEA Data service. This will be done using the existing GEA service test, as part of which the CP will be given an indication of whether the EU has been enabled to receive Multicast or not.

R1500

Reference ID Functionality Description ORC2M-8821

Diagnose Multicast Connectivity. You (CP) will be able to raise faults against the Multicast product and have those faults investigated and diagnosed for connectivity issues on the ECI network.

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Product Description

R1509

ORC2M-11314

Diagnose Multicast Connectivity. You (CP) will be able to raise faults against the Multicast product and have those faults investigated and diagnosed for connectivity issues on the Huawei network.

This story will deliver the same T2R functionality as ORC2M-8821 but for the Huawei network.

R1700

ORC2M-12748 Service test update for active Multicast IGMP joins. A diagnostic test option that reports the Multicast channels a User port is .

ORC2M-14348 Reporting interface for CPs to provide VDSL errored seconds. ORC2M-15098 FTTC: inclusion of VDSL errored seconds in GEA service test.

8.3 Additional EMP stories

R1600

The release aims to enable a small footprint Pilot of the Multicast functionality involving 1 or more CPs with friendly end users and drive the learning to enable a launch product. There are three stories that aim to expand the functionality of Multicast delivered in R1500/1509 and described previously.

ORC2M-11854

The story enables CPs to prioritise some Data traffic (e.g. derived voice) above the Multicast traffic on a specific FTTC/FTTP line. Specifically, the CP will be able to use the Ethernet .p marking value of 4 to prioritise Data traffic on the line above Multicast which uses the priority marking of 3. This story is in response of industry requests via TWG.

ORC2M-12735 The story will enable the modifying of a Multicast VLAN size on ECI equipment to enhance the L2C functionality offered in R1500.

ORC2M-13742

This story delivers a strategic fix for Siebel, which will enable the association of a CP’s EU to a Multicast VLAN using standard interfaces instead of a tactical approach currently used.

9 Commercial

Openreach will aim to provide consistent pricing for Multicast operating across both FTTC and FTTP infrastructure. Openreach would offer GEA-Multicast to support mass market service delivery and will price the product appropriately with charging that is simple and predictable. A minimum contract period (12 months) of service for each Multicast VLAN would apply.

One off charges

 A charge would be made to establish each Multicast VLAN.

 A modify charge for any change of configuration of bandwidth of the Multicast SVLAN

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Product Description

 A fixed rental per Multicast VLAN planned on a sliding scale based on bandwidth (e.g. 5, 10, 15Mbit/s and then per additional 5Mbit/s increments up to 200Mbit/s then in 10Mbit/s increments up to 300Mbit/s).

Other notes

 There is no provision or service charges on a per User basis.

 Multicast will be default enabled as part of your initial Multicast set up.

 Modifications of bandwidth during the first 12 months would be upward only.

 Subsequent modifications may be limited to one a month.

10 Glossary of Terms

Abbreviation Full Name

ASM Any Specific Multicast

BRAS Broadband Remote Access Server BT British Telecommunications plc CP Communications Provider CPE Customer Premises Equipment DHCP Dynamic Host Configuration Protocol DSLAM Digital Subscriber Line Access Multiplexer

EU End User

FTTC Fibre To The Cabinet FTTP Fibre To The Premise

FTTx Fibre To The x (where x could be C or P) FVA Fibre Voice Access

GEA Generic Ethernet Access GPON Gigabit Passive Optical Network IGMP Internet Group Management Protocol LAG Link Aggregated Group

LAN Local Area Network L2C Lead to Cash

L2S Layer 2 Switch (incorporating OLT)

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Product Description

NGA Next Generation Access

NTE Network Termination Equipment Ofcom Office of Communications [UK] OLT Optical Line Termination ONT Optical Network Termination PIR Peak Information Rate PON Passive Optical Network

PPPoE Point-to-Point Protocol over Ethernet QoS Quality of Service

SRM Sales and Relationship Manager SSM Source Specific Multicast

STB Set Top Box

SVLAN Service Virtual Local Area Network T2R Trouble to Repair

VLAN Virtual Local Area Network

UNI User Network Interface (e.g. data port on ONT)

Internet Group Management Protocol