On Tue, 20 Apr 2004, Patrick W.Gilmore wrote:
In many, many cases, especially for smaller providers, this is a spare FE on a switch which already exists.
I assume Vijay meant the cost of a port for private peering, in which case if you private with all your peers and you have a lot of small peers thats going to be a lot of cost for a few kbps of traffic
- Operational costs such as legal review for BLPAs, NOC monitoring, troubleshooting when it flaps, putting MD5 on, etc
These costs are frequently quoted as reasons not to peer by the larger providers.
BLPAs are only required by people who think they mean something.
Well theyre a good excuse thats for certain :) But I would say they do mean something.. if you're BigISP-A and you are peering with BigISP-B you want to make sure that continues reliably and that means a formal arrangement. Even if your a small ISP its worthwhile considering a formal arrangement particularly with the larger peers to make sure they dont ditch you without some good notice or that they will upgrade without cost if your traffic increases....
In general, Peering is a Good Thing [tm]. It increases performance, can lower costs, and might even increase your network reliability.
Hmm, we're fairly open on peering and have a bunch of small peers, in fact most of our new peerings are with small peers (small is something like announcing a single /24 and doing almost no traffic). We occasionally see performance problems with these small peers, where they maybe drop the session without warning raising an alarm here or do something screwy with their config and leak or whatever. They also tend to only have one connection, this forces how we route traffic to them, as we're in the process of expanding I really want to have multiple equal paths so that we can be sure the traffic is taking the best way to them. My summary of these points is that I'm seriously considering what our policy will be in the future and for good reason (altho it will undoubtedly continue to be fairly relaxed).
If your monthly costs are lower with peering than transit alone, it is probably a good idea to peer and ignore the NOC costs.
In some instances I'm willing to pay more for a connection (eg paid peering or costs of backbone circuits) to ensure I'm receiving quality. There are a couple other issues not raised... One is the cost on the router in terms of memory and cpu of maintaining such a large number of sessions (usually less of an issue with your big multiprocessor routers) The other is our new hot topic of security, not sure if anyone has thought of this yet (or how interesting it is) but the nature of the bgp attack means that if you can view a BGP session you can figure things about a peer that would otherwise be hidden from you in particular the port numbers in use.. and I'm not entirely clear on the details but it sounds like when you hit the first session, you can take the rest out very easily. We cant take BGP out of band (yet!), perhaps we can keep it better hidden from view tho.. Steve