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| Internet protocol suite |
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| Application layer |
| Transport layer |
| Internet layer |
| Link layer |
IEEE 802.1aq is an amendment to the IEEE 802.1Q networking standard which adds support for Shortest Path Bridging (SPB). This technology is intended to simplify the creation and configuration of Ethernet networks while enabling multipath routing.[1][2][3]
SPB is designed to replace the older spanning tree protocols: IEEE 802.1D STP, IEEE 802.1w RSTP, and IEEE 802.1s MSTP. These block any redundant paths that can result in a switching loop, whereas SPB allows all paths to be active with multiple equal-cost paths, provides much larger layer-2 topologies,[4] supports faster convergence times, and improves the efficiency by allowing traffic to load share across all paths of a mesh network.[5][6][7][8] It is designed to preserve the plug-and-play nature that established Ethernet as the de facto protocol at layer 2.
The technology provides VLANs on native Ethernet infrastructures using a link-state protocol to advertise both topology and VLAN membership. Packets are encapsulated at the edge either in MAC-in-MAC per IEEE 802.1ah or tagged per IEEE 802.1Q or IEEE 802.1ad and transported only to other members of VLAN. Unicast, multicast, and broadcast are supported and all routing is on symmetric shortest paths.
The control plane is based on the Intermediate System to Intermediate System (IS-IS) routing protocol, leveraging a small number of extensions defined in RFC 6329.[9]
- ^ "Alcatel-Lucent, Avaya, Huawei, Solana and Spirent Showcase Shortest Path Bridging Interoperability". Huawei. 7 September 2011. Retrieved 11 September 2011.
- ^ Luo, Zhen; Suh, Changjin (3 March 2011). "An improved shortest path bridging protocol for Ethernet backbone network". The International Conference on Information Networking 2011 (ICOIN2011). IEEE Xplore. pp. 148–153. doi:10.1109/ICOIN.2011.5723169. ISBN 978-1-61284-661-3. ISSN 1976-7684. S2CID 11193141.
- ^ "Lab Testing Summary Report; Data Center Configuration with SPB" (PDF). Miercom. September 2011. Retrieved 25 December 2011.
- ^ Shuang Yu. "IEEE approves new IEEE 802.1aq™ Shortest path bridging". IEEE Standards Association. Archived from the original on 14 May 2013. Retrieved 19 June 2012.
Using the IEEE's next-generation VLAN, called a Service Interface Identifier (I-SID), it is capable of supporting 16 million unique services compared to the VLAN limit of four thousand.
- ^ Peter Ashwood-Smith (24 February 2011). "Shortest Path Bridging IEEE 802.1aq Overview" (PDF). Huawei. Archived from the original (PDF) on 15 May 2013. Retrieved 11 May 2012.
- ^
Jim Duffy (11 May 2012). "Largest Illinois healthcare system uproots Cisco to build $40M private cloud". PC Advisor. Retrieved 11 May 2012.
Shortest Path Bridging will replace Spanning Tree in the Ethernet fabric.
- ^ "IEEE Approves New IEEE 802.1aq Shortest Path Bridging Standard". Tech Power Up. 7 May 2012. Retrieved 11 May 2012.
- ^ D. Fedyk, Ed.; P. Ashwood-Smith, Ed.; D. Allan, A. Bragg; P. Unbehagen (April 2012). "IS-IS Extensions Supporting IEEE 802.1aq". IETF. Retrieved 12 May 2012.
- ^ Unbehagen, Paul; Bragg, Nigel; Allan, David; Fedyk, Don; Ashwood-Smith, Peter J. (April 2012). Fedyk, D; Ashwood-Smith, P (eds.). IS-IS Extensions Supporting IEEE 802.1aq Shortest Path Bridging. IETF. doi:10.17487/RFC6329. RFC 6329.