Smooth Sailing for VLAN Standard
The 802.1ad working group in the Institute of Electrical and Electronics Engineers Inc. (IEEE) has all the makings of a good brawl, namely a vital network technology being discussed by competing vendors. But, alas, the fists weren't flying last week when the group met in San Francisco.
“So far there is no controversy to report,” says Tony Jeffree, chairman of the working group. “There are always some minor disagreements in the early stage of developing a standard, but there hasn’t been anything major.”
One of the reasons the group might be working so well is because it has a clearly defined a purpose and a problem it’s trying to solve. The 802.1ad group is working to define a common way to implement virtual LAN (VLAN) stacking in Ethernet switches. VLAN stacking is a technology that allows carriers to slap on a public VLAN tag onto packets, so that they can be transported over a metro network. The important thing about the technology is that it maintains the integrity of the traffic, and it keeps one customer’s traffic separated from another’s traffic.
Most Ethernet switch vendors are already using their own implementation of VLAN stacking, and that's making carriers reluctant to deploy metro Ethernet at all. Getting locked into one vendor can be expensive. But a standard could help spur deployments, because carriers will be able to benefit from dual sourcing. This allows them to play one switch vendor against another for the best deal.
“We had to buy all of our Ethernet switches from a single vendor,” says Bob Klessig, director of engineering at Cisco Systems Inc. (Nasdaq: CSCO), who founded Telseon Inc.. “We could make it work, but in the long run we would have preferred to have multiple vendors to choose from.”
Another key reason things have been going so smoothly could be because the proposed fixes are not rooted in hardware. In the end, for vendors to comply with the standard, they’ll simply have to upgrade their switches with a new revolution of software.
“It’s always much harder and more expensive to change hardware,” says Craig Easley, a director in the office of the CTO at Extreme Networks Inc. (Nasdaq: EXTR). “That’s what happened with RPR.”
Ah, yes. The Resilient Packet Ring (RPR) working group. Recall that the RPR group once split into two camps fighting over how best to implement the technology for almost two years. Cisco was on one side of the battle, while Nortel Networks Corp. (NYSE/Toronto: NT) was on the other (see RPR Divided). Those were the days.
While the RPR debate centered around technology, the heart of the disagreement had to do with the fact that Cisco and Nortel each had their own proprietary versions of hardware already deployed in customer networks. Neither group wanted to spend the time or the money to make the necessary changes. In the end, the two companies compromised, and a new standard was formed that resembled neither Cisco’s nor Nortel’s implementations (see Cisco in U-Turn on RPR and IEEE Approves RPR Working Ballot).
The disagreement made carrier customers even more hesitant to deploy new RPR gear for fear that the vendor they chose wouldn’t comply with the standard. It also forced some vendors to spend more time, effort, and money on parallel technology development.
This time around, however, vendors involved in the 802.1ad development have been very accepting of proposals from Cisco. “Instead of pushing to do things their way, they have already been compromising” says Easley. “I think that has made the other vendors involved more comfortable. They haven’t been trying to force anything down anyone’s throat to get a leg up.”
Rest assured, though, when the throat ramming and leg upping begins, we'll be there!
— Marguerite Reardon, Senior Editor, Light Reading