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ISP BGP Question

Hi Guys,

I Have a quesiton relating to peering arragements between ISPs at Peering Points around the globe. We have a presense at LINX and MANIX in the UK. And pratially every day we get requests from other ISPs that have a presence here to peer.

My Questions are,

Is it good practice to establish as many peering arragements as possible?

What is the limit of peering arragemnents?

What is the hardware limit in terms of peering arragements (with prefix lists in place)?

Generally, i would like to know other ISPs experience here. WE intend providing content services early next year and out CTO thinks that as many peering arrangements as possible is a good idea. Especially with big isps.

Thanks in advance


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Re: ISP BGP Question

Hello Stephen,

establishing peering arrangements in IXC like LINX or AMSIX does not have additional costs you are there for peering.

However, not all peering relationships are equal.

Accepting all requests can be good at the beginning.

After some time you should evaluate the quality of each peering relationship.

In a internet exchange point you can combine netflow and MAC address accounting to understand the volume of traffic received and sent to each peer in a period of time.

When speaking of peering relationship you are not going to receive full BGP internet tables like the ones you receive from your upstream providers.

You can have 20 to 40 eBGP sessions at LINX on a GSR box or 7600 without great problems.

If you are a content provider is your interest and that of ISPs to have a direct peering relation.

The target of the game is to move traffic quotas from paid bandwidth on links to upstream providers to links where traffic is not paid on volume.

Tier2 ISPs all implement form of peering assessment and evaluation and don't accept relationship with everyone.

So this is a job that requires some periodic reviews.

To confuse things further you can have a peering relationship with one or more of your upstream providers if they accept.

Hope to help


Re: ISP BGP Question

That was quite an informative answer by Giuseppe.

Re: ISP BGP Question

Hi Giuseppe,

Thanks for the info here. It appears that creating a peering relationship with everyone that asks for it is perhaps not the best idea, but with careful scrutiny and management one can deveople good working relationships with peers that can work to everones benefit.

I also appreciate the point on traffic management, there is not much point on having peering relationships with ISPs where no traffic is coming between us. I think beacuse we will be proving content services next year it may be a good start to peer up with the major 'end-user' isps like BT and virgin etc... That way the users will have the shortest path to our services.



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