Extending Network-virtualization Platforms by using a Specialized Packet Header and Node Plug-ins. Yasusi Kanada Hitachi, Ltd.

Extending Network-virtualization Platforms

by using a Specialized Packet Header

and Node Plug-ins

Yasusi Kanada

Hitachi, Ltd., Japan

Outline

►VNode infrastructure is an architecture and testbed for network virtualization.

■ A VNode means a physical network node (not virtual node).

■ Developers can create slices (i.e., virtual networks) using predefined virtual-resource types.

►A plug-in architecture for VNode, which was proposed in previous papers, enables introducing new types.

■ Slice developers may require new virtual-resource types.

■ New virtual-resource types can be defined and implemented by using the plug-in architecture.

►Proposal: A method using plug-in-specific (resource-type-specific) packet headers

■ This method enables introducing new network-wide functions by new resource-type and plug-ins without modifying slices.

VNode Infrastructure and Slices

►Developers can create slices using predefined virtual-resource types (i.e., virtual-node and -link types).

VNode VNode VNode Virtual node Virtual node Virtual node Slice developer . . . . . . Management node

<linkSliver type="link" subtype="GRE"> <vports> <vport name="vport1" /> <vport name="vport2" /> </vports> </linkSliver> <nodeSliver> <instance type="…" subtype="SlowPath_VM"> … </instance> <vports> <vport name="vport1"/> … <vport name="vportN"/> </vports> </nodeSliver> VNode infrastructure Slice (virtual network) Slice definition VNode Predefined types Predefined types Deeply programmable Operator

VNode VNode VNode Virtual node Virtual node Virtual node Slice developer . . . . . . Management node <linkSliver type="link" subtype="new-link-type"> <vports> <vport name="vport1" /> <vport name="vport2" /> </vports> </linkSliver> <nodeSliver> <instance type="…" subtype="new-node-type"> … </instance> <vports> <vport name="vport1"/> … <vport name="vportN"/> </vports> </nodeSliver> VNode infrastructure Slice Slice definition VNode Predefined types New types

Plug-in Architecture

►New virtual-resource types can be defined and implemented by using the plug-in architecture.

New resource types (new function) Plug-ins Plug-ins Plug-ins Plug-ins Added by the operator (or vendor) Operator

VNode VNode VNode Virtual node Virtual node Virtual node Slice developer . . . . . . Management node <linkSliver type="link" subtype="new-link-type"> <vports> <vport name="vport1" /> <vport name="vport2" /> </vports> </linkSliver> <nodeSliver> <instance type="…" subtype=“old-node-type"> … </instance> <vports> <vport name="vport1"/> … <vport name="vportN"/> </vports> </nodeSliver> VNode infrastructure Slice

Old slice definition

VNode New link

type

Platform-extension w/o Slice Modification:

New Proposal

►The proposed method enables introducing new

network-wide functions by new link-type and plug-ins without modifying slices.

Plug-ins

No new function (no update in programs) New network-wide substrate function Plug-ins Plug-ins Plug-ins Co-operation Co-operation Co-operation Co-operation Operator

Platform-extension w/o Slice Modification:

Method

►New functions and co-operation of plug-ins are

introduced by resource-type-specific packet headers.

►Data plane is extended:

Base platform

header header 1Plug-in

VNode Plug-ins Data plug-in 1 Base data-plane component Data plug-in 2 Data plug-in 3 Data plug-in 4 Plug-in

header 2 header 3Plug-in header 4Plug-in Packet on slice Platform header

Packet

Extended VNode VNode

Plug-ins

Example of Using Platform-extension:

Network-wide Delay Measurement

►Network-wide delay can be measured without affecting slice design/implementation by using a new link type.

►The plug-in header contains a timestamp.

VNode VNode VNode Virtual node VNode infrastructure Slice VNode

Terminal _Virtual Terminal

node Virtual node

Packet Packet Packet Packet Plug-in Plug-in Plug-in Plug-in Time = 0 Time?

Ingress edge Egress edge

Packet

ts ts Packet

Timestamp Timestamp

Timestamp is hidden

Problem: Packet Identification

in Programmable Slices

►Packets must be identified to track them (i.e., to measure the delay).

►Packet identity depends on the node function.

■ Packets may be absorbed, generated, or duplicated by

the node program.

Virtual node

Slice

Terminal _Virtual Terminal

node Virtual node

Packet Packet Packet Packet must be identified VNode Virtual node VNode Virtual node packetNo VNode Virtual node No packet Packet Packet Packet Packet Packet

Solution: Slice Supplies Packet Id to Plug-ins

►The slice (developer) must define the identity of packets.

■ _{Simple identity: to specify identifier field.} ■ _{Generic identity: to specify identity function.}

►The plug-in identifies packets.

■ It removes and stores a platform header from a packet and restores it to the packet.

id p id = f(p) td id VNode Virtual node Plug-ins id id id td Restore Identify Remove and store

Evaluation: Conditions

►A VLAN-based link type with delay measurement function (called MVL type) was introduced.

►The plug-in for MVL type was implemented by using network processors (NPs).

■ Cavium Octeon NP with twelve 750-MHz cores was used.

►The delay between two simulated terminals with two VNodes were measured.

■ Two terminals were simulated by one PC to avoid synchronization problem. VNode VNode Octeon (NP) MVL link Octeon(NP) Measure-ment GW Terminal

(program) Measure-ment GW Terminal (program)

sw sw

MVL link _{MVL link}

PC for measurement

Timestamp handling and header conversion

Evaluation: Results

►Evaluation results

■ Delay: 89 µS (σ = 12 µS) / node.

■ Timestamp (TS) handling and header conversion (required for virtual-link processing: Implementation Throughput (Gbps) * Throughput (Gbps)* Program lines Implementation TS insertion TS deletion Program lines

NP program (in Phonepl) 10.0† 9.5† 99‡

Xeon program (in C)** _2.3† (4.0††) 2.2† (4.0††) 190‡

*_{Packet size: 1024 B.} ** _{Promiscuous mode is used.} †_{No packet loss (< 10}-6₎

Conclusion

►A method for introducing new functions without updating slice implementation is proposed.

■ Resource-type-specific (plug-in-specific) packet headers are used. ■ The packet headers are processed by the plug-in in each VNode.

►This method was applied to measurements of network edge-to-edge delay.

■ A hidden timestamp in each packet is used.

■ Timestamps do not affect slices; i.e., slices do not see timestamps.

►A virtual link with delay-measurement function was evaluated.

■ The throughput was 10-Gbps (i.e., wire rate). ■ The latency was less than 100 µS.

►Future work

■ Implementation of other node/link functions. ■ Handling multiple plug-in-specific headers.