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IP Multicast is like Banyan Vines

Every now and then I stumble upon an elegy lamenting the need to study IP Multicast to pass one or the other certification exam. The history obviously repeats itself; we’ve been dealing with similar problems in the past and one of my favorite examples is Banyan VINES.

If you’ve been working with Cisco routers for more than 15 years, you might still have fond memories of Router Software Configuration (RSC) course, at its time one of the best networking courses. In those prehistoric days, the networks were multi-protocol, running all sorts of things in parallel with IPv4. The week-long RSC course thus covered (at least) the following protocols: IPv4, AppleTalk, Novell IPX, DecNET, XNS, Banyan VINES, CLNP and SNA (I probably forgot one or two). By the third day, everyone (including the instructor) was sick-and-tired of the endless stream of lookalike protocols and ready to skip a section or two.

The Banyan VINES section was the obvious candidate, but I always had exactly one student in the class of 16-20 students that wanted to have it covered, because Banyan VINES configuration was the only reason he attended the RSC course. You see ... although (almost) nobody was using that weird protocol, it was used by a few “obscure” entities, including Coca Cola, Siemens, Ericsson and US Marine Corps.

IP multicast faces the same problem: almost nobody is using it, but the few people that do need it pretty badly; they range from Service Providers delivering 3-play services to financial institutions delivering live video feeds to trader floors.


  1. Ericsson used Banyan Vines at least into the late 90s.

  2. I remember taking the RSC in October '93. This was my first exposure to Cisco routers: think AGS+, IGS and IOS 9.1. By the time we got to CRB/IRB on Thursday afternoon, my brain was ready to pack up! Lots of fun all round... :)

  3. It's not live video feeds in financial institutions, the stock ticker itself---along with every other type of imaginable trading-relevant data---is done in IPv4 multicast. Working in the industry, I don't hire anyone that can't at least tell me the difference between SM and DM and what an (S,G) state is.

  4. Working at a SP delivering 3-play we see the complexity of IP multicast is underestimated. Everyone seems to think Multicast is seperate from Unicast. Usually they stop thinking that way when told to fix a RPF failure.

  5. Yap Chin Hoong23 March, 2010 15:20

    I wished I was borned earlier to learn those classic protocols. :-D

  6. I think could be intersting a statistical survey about who is using multicast in his network enviroment..., I work in a broadcast media an we are using multicast for our video distribution in a WAN/LAN scenario and we are very satisfied about it.

  7. Ericsson (I like the red touch) should have stuck with it. Certainly they did better job than with any of their IP products.

  8. another one is forgotten - X.25 ! :)

  9. I would say Multicasting is a far less obscure thing than Banyan Vines.

    The financial industry uses it quite a bit and also employs quite a few engineers to keep it all running...


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