Posted by: Shamus McGillicuddy
converged networks, data center networks, Extreme Networks, Networking, shortest path bridging, spanning tree protocol, TRILL
As the IETF and the IEEE finish baking their similar, but competing standards – Transparent Interconnects of Lots of Links (TRILL) and Shortest Path Bridging (NPB) – Extreme Networks is offering a software upgrade that delivers one of the benefits of TRILL and SPB today, without any hardware replacement.
TRILL and SPB promise to solve several architectural issues in data center networks today. Extreme aims to emulate just one of the benefits of the emerging standards. TRILL and SPB free up unused bandwidth in a network caused by spanning tree protocol (STP). STP prevents loops from forming in a network topology by closing off redundant paths. Those redundant paths only open if the primary link fails. TRILL and SPB allow all redundant links to be open, which allows Ethernet frames to take the shortest path to their destination. SPB and TRILL also allow multiple links to be in active-active mode, with data traffic aggregating across them.
Both TRILL and SPB are available today in a small amount of pre-standard products from some vendors. The use of TRILL and SPB will require hardware upgrades, so enterprises that want to benefit from the technology will have to replace their network infrastructure.
Extreme Networks has introduced a software upgrade across its switching portfolio that can give enterprises a portion of the functionality TRILL and SPB promises. And it delivers this capability without requiring new hardware.
Extreme has combined its Direct Attach Virtual Machine switching feature with its Multi-System Link Aggregation (M-LAG) feature to deliver a new “M-LAG Direct Attach” architecture. Basically, this software upgrade allows a customer to set pairs of upstream links in active-active mode, which enables upstream link aggregation.
“This provides enterprises the ability to have an active-active path in the data center today,” said Shehzad Merchant is the Senior Director of Strategy for Extreme. “Link aggregation technology has been around a long time. We’ve taken that technology and extend it. Now you can take a server with two NICs and bond those NICs with link aggregation and dual-home those into two upstream switches. If one switch or one NIC goes down, traffic automatically migrates to the second link. But if both are up, traffic aggregates across both those links.”
Unlike TRILL and SPB’s ability to work with arbitrary, multi-homed topologies, Exteme’s M-LAG Direct Attach only works with dual-homed links. M-LAG Direct Attach is also a proprietary technology, so you will need Extreme switches both upstream and downstream to make it work.