i operate network with some AS. one AS we use for transit traffic and connecting to the upstream, all another use for regional branch -- With best regards, Andrey 'sshd' Petrenko xmmp\gtalk: andy.petrenko at gmail.com skype: andy.petrenko web: http://sshd.by
On 06.12.2012, at 15:21, Reuben Farrelly <reuben-cisco-...@reub.net> wrote: > On 6/12/2012 10:54 PM, mert ozkul wrote: >> Hi All, >> I have query about ISP Design. >> Why some ISP`s (Ex: BT) using dual AS`es on their network? >> What are the advantages of using more than one AS in the ISP network?What >> can be achieved if you use more than one AS? >> Thanks,Best Regards, >> -Mert > > I operate a network where we have two AS's. We inherited the second AS when > we took over the second network. > > Why haven't we merged this into one big AS? Well the two AS's have two > completely separate routing policies. One of those AS's supplies only > schools as downstream users, and the upstream connectivity to them is via a > specific supplier (a regional educational/research network) whose rules of > engagement are that they only supply to education/non corporate clients. > > Our other AS is a bit more relaxed, and there is no such restriction with any > suppliers to that network. > > The two AS's peer with each other though so it doesn't cost anything for data > to transit between them anyway. > > It does pose some fairly minor complications in terms of training and > one-bgp-as-per-IOS but given we have full control over both AS's and all the > equipment in them, it means on the other hand that we get to work with some > slightly more exciting things like inter-AS MPLS that you don't get to > experiment with when it's all one vanilla system ;-) > > Just one reason why an ISP may have more than one AS. > > Reuben > > > _______________________________________________ > cisco-nsp mailing list cisco-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
