North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: maximum active vlans in a cisco 6509

  • From: Julian Eccli
  • Date: Wed Jun 21 22:46:19 2000

>okay, now let's change venue:
>the hotel has copper pairs to all of the rooms that are terminated on a
>dslam. this dslam has only ethernet out and on the  segment can provision
>each cable pair/customer to a vlan. these vlans are then aggregated into
>10/100 switches in the basement uplinked to the corporate office via gige.
>then all those customer vlans end up being bridged 1483 to atm pvcs into an
I think you have been playing with Nortel far too long.  This was there old
and a great way to get rid of their first generation DSLAM's which are the
Star Hubs that hang off a DMS switch.  Basically a DMS and Star Hub, the
Hub connects to a Xylan O/S which does 1483B/R to a Shasta SSG-5000 which
connect to a router and then the destination network...The DMS has a leased
pipe to the star hub to provide the voice portion.  xDSL only soultion up to
1.3 Meg
and a seven foot rack can only support 500 subs and costs about $300,000 or
something like that, a tad pricey and very little sub to space ratio and
management software as well.

Nortel's new Prometory DSLAM's should fare much better and are true ATM
through and through instead of badly hacked DSL to Ethernet to ATM.
Prometory's are
nice boxes and they even do PNNI and allow for up to 128 VCC's per DSL port
which can offer a ton of nice services to a destination node.  We just got
some in and
ordered about 30+ more of these units, easy to set up and configure.

>what box could possible aggregate all this gige, sar to atm, all the while
>supporting thousands of vlans
>many thanks from hotel owners everywhere 8>

Well, unless your average hotel customer or possibly the Maid's are major
bandwidth hogs (All those lonely people in those plush and warm hotels.
Well, now
we know why they are typing with only one hand!) and accessing FTP/Napster
exclusively I don't think you would have to worry much about the BW
utilization at
this time.

The thousands of VLAN's could be done with thousands of PVC's, just
get rid of the VLAN's in this scenario for DSL.  Each box that maybe has 500
DSL access ports will aggregate to either one or just a few PVC's for back
haul to either
be routed or aggregated again so I seriously doubt you will have thousands
of anything in
a single box, at least in the near future.  Else some of the other comments
about building out a building and using switch ports as VLAN'ed router sub
interfaces works just great up to about 40-60 VLAN's per 100 Meg port on
a VIP module (My experience from doing this) and with CAR you can even
setup a poor man's Packeteer BW management for free!

Have never gone over 150 VLAN's in a box, so I do not know the upper limit,
although it is 250 to my understanding.