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Cisco in U-Turn on RPR

Light Reading
News Analysis
Light Reading
11/20/2001

Cisco Systems Inc. (Nasdaq: CSCO) has taken a big U-turn on its efforts to influence the direction of the proposed standard for resilient packet ring (RPR) networks. Instead of trying to bulldoze folk into accepting its spacial reuse protocol (SRP), a technology already widely deployed by Cisco, it’s dropped the idea altogether and proposed something called “Gandalf.”

Gandalf will require Cisco and its followers to re-spin SRP silicon and won’t give them an inside track in terms of having an existing installed base, according to a presentation they gave to the 802.17 working group of the Institute of Electrical and Electronics Engineers Inc. (IEEE) in Austin, Texas, last week. The presentation makes a big thing out of saying that “Gandalf is not compatible with SRP” and that it’s “not backwards compatible with any existing implementation.” The paper is posted on the IEEE802.org Website at http://www.ieee802.org/17/documents/presentations/nov2001/sw_over_03.pdf

Contributors to the Gandalf paper include Cisco and other vendors already making SRP products, such as Riverstone Networks Inc. (Nasdaq: RSTN) and Mindspeed Technologies.

Other contributors include Agere Systems (NYSE: AGR), Sun Microsystems Inc. (Nasdaq: SUNW), Infineon Technologies AG (NYSE/Frankfurt: IFX), Fujitsu Network Communications Inc. (FNC), Broadcom Corp. (Nasdaq: BRCM), Redwave Networks, Corrigent Systems, Appian Communications, Lara Networks Inc., and DataNet Associates.

Cisco’s opponents in the IEEE 802.17 working group, which have already joined forces to promote a technology called Aladdin as the basis of the RPR standard, acknowledge Cisco’s efforts. “They’ve shown they're willing to change, and that’s very positive,” says Raj Sharma, director of product marketing at Luminous Networks Inc. and vice chairman of the Resilient Packet Ring Alliance.

Other Aladdin backers include Alcatel SA (NYSE: ALA; Paris: CGEP:PA), NEC Corp. (Nasdaq: NIPNY), Nortel Networks Corp. (NYSE/Toronto: NT), Lantern Communications Inc., Vitesse Semiconductor Corp. (Nasdaq: VTSS), and Scientific-Atlanta Inc. (NYSE:SFA).

Sharma says that Gandalf is a big improvement over SRP because it addresses the fundamental goal of the proposed RPR standard -- to provide a way of enabling carriers to offer three types of service. These are: where bandwidth is dedicated to particular connection; where service-level agreements (SLAs) are offered, but traffic shares bandwidth; and best-effort services. SRP only offers dedicated and best-effort services; it doesn’t incorporate weighted bandwidth reservation, which is required for SLAs.

However, there’s still a fundamental difference between Gandalf and Aladdin, a difference that will be hard to reconcile. Aladdin works on the basis of preventing congestion happening in the first place -- a traditional telecom approach. Gandalf works on the basis of detecting congestion and then dealing with it -- the approach used in router networks. Sharma contends that the latter approach can’t provide the same level of performance guarantees, because there’s bound to be a time lag between detecting and dealing with congestion.

Cisco wasn’t able to field anybody to talk about Gandalf by press time.

It’s worth pointing out that Cisco’s shift in strategy in the RPR standards group probably won’t have a big impact on customers that have already installed its SRP-based equipment. That’s because the technology within rings can be proprietary, so long as the connections to the rings comply with the standard, whenever that finally emerges.

The big question is whether the standard will ever emerge. This latest development hasn’t moved the process forward at all. In fact, it’s probably moved it backward, because Gandalf isn’t much more than an idea right now. For instance, last week’s presentation to the IEEE working group noted that a comparison with Aladdin wasn’t complete because of “a problem with the current simulator.”

All of this may also be a case of fiddling while Rome burns. RPR might be a groovy idea, but a lot of carriers are likely to stick with Sonet to build their metro networks, because it’s proven technology and most of their revenues are generated by traffic travelling across TDM (time-division multiplex) channels. Other carriers are likely to try Ethernet rather than RPR, on the basis of it being backed by a whole industry, driving down costs, coupled with a huge established base in customer sites (see RPR: RIP?).

— Peter Heywood, Founding Editor, Light Reading
http://www.lightreading.com Want to know more? This very topic is the subject of a session at Lightspeed Europe,Light Reading’s annual conference, on December 4-6, 2001, in London. Details: [Metro Networks: Latest Developments

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linkv
linkv
12/4/2012 | 7:32:41 PM
re: Cisco in U-Turn on RPR
Peter - why do you think Cisco's willingness to
compromise within the IEEE802.17WG is a negative?
There was a great deal of convergence during the
meeting between the two groups. The standard is
not only right on track, but looking good to be
complete ahead of original schedule.

Oh, just btw, the carriers appear to be quite
serious about RPR, contrary to your inflamatory
closing statements.

linkv
packet_man
packet_man
12/4/2012 | 7:32:41 PM
re: Cisco in U-Turn on RPR
Just a note, you said:

The big question is whether the standard will ever emerge. This latest development hasnG«÷t moved the process forward at all. In fact, itG«÷s probably moved it backward because Gandalf isnG«÷t much more than an idea right now. For instance, last weekG«÷s presentation to the IEEE working group noted that a comparison with Alladin wasnG«÷t complete because of G«£a problem with the current simulatorG«•.

Having sat throught the entire 802.17 meeting, I must say that your statement that this step hasn't moved things forward at all is absolutely wrong! Gandalf has been the Cisco proposal all along, and they are making major concessions, moving towards common ground with Alladin. In fact, the overall feeling at tthe end of the meeting was that HUGE steps were being made. Gandalf is far more than an idea, and so is Alladin, The comparisons you note - failing because of a problem with the current simulator, was NO BIG issue. It was mentioned because the effort is being made to quantify the actual differences in performance - something you can't do with "just an idea".

My hope is that you won't just look for the way to spin this news as bad but rather talk to a few more people who actually attended - its obvious you didn't - and get the real story! 802.17 is moving towards a standard quicker than most people thought!

pm
poster
poster
12/4/2012 | 7:32:40 PM
re: Cisco in U-Turn on RPR
so you're damned if you compromise becuase it's just a standard still, with no live traffic and requires more development and you're damned if you don't becuase you're railroading the standards process with with your vested interest with technology that's already been deployed in 13000 ports.

makes a lot of sense Peter.
Peter Heywood
Peter Heywood
12/4/2012 | 7:32:40 PM
re: Cisco in U-Turn on RPR
I'll eat a little...

I've just removed the bit about Cisco eating humble pie, which was un-called for.

I wasn't intending this to be negative about Cisco. Cisco obviously deserves praise for doing something to placate the folk it angered in the IEEE.

The point I was making towards the end is that Gandalf, like Aladdin, is merely a proposal for a standard. In this respect, it's got more to prove than SRP, which actually exists in live networks.


poster
poster
12/4/2012 | 7:32:39 PM
re: Cisco in U-Turn on RPR
who's making the U turn now? and I don't even work for Cisco...
HarveyMudd
HarveyMudd
12/4/2012 | 7:32:34 PM
re: Cisco in U-Turn on RPR
It is very difficult to understand as to why cisco would not fully support the RPR standard currently being worked on IEEE 802.17 comittee. It is all the more difficult for me to understand as Cisco recently bought an RPR chip company and announced that it would license the technology to other vendors. Is the change of heart on the part of the Cisco because the chip is not working.

Cisco has not given any reason not to adhere to proposed IEEE standard.

Lumniscent has some version of IEEE 802.17 working and has marketed the product ( if true) to an unknown carrier. In fact RPR is claim to fame ( if this is the right word). All these claims need to be examined very deeply before the whole politics of standards can be evaluated.

By the way I do nopt like names like Alladin and Gendalf. These names are serious diservice to the standards bodies.
fabless
fabless
12/4/2012 | 7:32:34 PM
re: Cisco in U-Turn on RPR
Having sat through numerous 802.17 meeting, I have a number of issues with the article as written. Another commenter made the "dammed if you do" comment and I agree. Cisco plays the 802.17 game honestly, they annoy people, but there are no hidden agendas, they come right at you and say what they want to do. Thats the mistake of sending engineers to do a marketing job.

In September, Cisco presented a proposal that was not backwards compatible with SRP because they changed the frame format. They did not bother to make a splashy show of it and so maybe people missed it. There is no doubt that Gandalf represents more movement toward concensus, but
the about face already happened, people just missed it. Must be the shock of Sept 11th.

It is interesting that this was not caught by people in September and probably explains the ad-nauseum repetition of Gandalf is not SRP. However, Gandalf does seem to have a few more wrinkles in it than the september proposal.

I would argue that because Cisco has chosen to add features in specific areas (and not others), Gandalf will benefit from the years of SRP deployment. Can the same be said for the other two proposals?

As to the comments about simulators, the impression I got at the meeting was that the Alladin simulator was not ready for prime time. Cisco ran a comparison run against Alladin. They returned the result to the Alladin group and did not present it to the working group as they were informed there was a problem with the Alladin simulator. Cisco did present a simulation study of Gandalf showing a key operation point - both single and dual tb nodes in the same ring.

I look forward to seeing what comes out of January. There may be more concensus, or it may stall out. The key is the people in the middle, we already know how Alladin and Gandalf supporters will vote.


knave
knave
12/4/2012 | 7:32:29 PM
re: Cisco in U-Turn on RPR

Cheers Harve, P.s. wait until the Tolkien estate hears about this one.

Can you say dead-Canadian-modem company...
Scott Raynovich
Scott Raynovich
12/4/2012 | 7:32:25 PM
re: Cisco in U-Turn on RPR
>Lumniscent
??

>By the way I do nopt like names like Alladin and >Gendalf. These names are serious diservice to >the standards bodies.

Harvey, you are losing it...
Peter Heywood
Peter Heywood
12/4/2012 | 7:32:23 PM
re: Cisco in U-Turn on RPR
I've now talked to Cisco and a bunch of other folk and plan to write a follow-up story. I'm aiming to post it on Friday.
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