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IETF SDN standards emerge: Southbound protocols, NFV, service chains

The new IETF SDN standards group, I2RS, will work on southbound programming protocols, NFV and network service chains. And that''s just the start.

After some fits and starts, the IETF furthered its work on SDN standards development last week, forming a group called The Interface to the Routing System (I2RS) with two major goals. The first is to standardize network-wide, multilayer topologies that include both virtual and real elements, network overlays and underlays. The second is to standardize the routing information base (RIB) programming of a device (virtual or real).

On the surface this might seem orthogonal to anything related to SDN -- especially considering RIB is used in traditional networking. But do not forget that one of the primary functions of an SDN controller is to program forwarding entries of the devices it controls. Typically we hear about doing this using OpenFlow. But OpenFlow has decided pros and cons. In particular, the low-level, hyper-granular and often per-flow programming nature of OpenFlow is undesirable to a good number of network operators who are familiar and very comfortable with programming devices at a route or policy level. I2RS has set out to do this with RIB. RIB programming could be used in conjunction with OpenFlow.

I2RS: NFV and network service chains

Another unofficial goal of I2RS would be to program Network Features Virtualization (NFV) service chains.

A brand new effort at the IETF called Network Service Chaining (NSC) is in its embryonic stage and not yet an official working group. Instead the group is still in the Birds-of-a-Feather (BoF) discussion stage. The goals of a BoF are to investigate whether there is sufficient interest in the IETF community to do work in a particular area. The group will also work to describe and define that area in sufficient detail so as to guide and steer the work to completion.

Specifically, this NSC BoF will work to align with the goals set forth by the ETSI NFV Group to produce protocols that can be used to signal and maintain network service chains. Information about the NSC BoF is publicly available as is information about how to attend or listen into the live stream during the meeting.

IETF SDN standards work with OpenDaylight

More on SDN standards

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Using BGP as an SDN protocol

Understanding OpenFlow configuration protocols: OF-Config and OVSDB

OpenFlow: A guide

OpenDaylight works to be truly open

InCNTRE's SDN and OpenFlow testing lab

While I don't think that the goals of the IETF are to define everything for SDN, there definitely is some interesting and useful work underway there. The IETF's work easily fits into other related projects, such as OpenDaylight's controller, where there is already a south-bound plug-in being worked on for I2RS, as well as a Topology Manager module based on most of the active Topology Yang models proposed there.

I should also mention that while the above two items are new, there are other SDN-related activities that have been underway for some time. These include Path Computation Element (PCE), Network Configuration (NetConf) and Application Layer Traffic Optimization (ALTO). In their totality, these efforts can be combined to form some interesting and important contributions to the SDN space.

These standards are schedule to be published by February 2014, according to the IR2S charter. Learn more information about I2RS work, including its discussion forum and mailing list, active documents (i.e., drafts) and charter.

About the author: Tom Nadeau is a Distinguished Engineer in the PSD CTO Office at Juniper Networks where he is responsible for leading all aspects of software-defined networks and network programmability. Tom has a new book, SDN: Software Defined Networks, An authoritative Review of Network Programmability Technologies coming out from O'Reilly Publishers in August 2013. Tom is an active participant in the IETF, ITU and IEEE. He is co-author of numerous protocol, architecture and MIB documents in the MPLS, BFD, L2/L3 VPN, MPLS-TP, pseudo-wire and traffic engineering areas.

This was last published in July 2013

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