If you're treating them as two separate links (e.g. two POPs, etc.) then that's correct, it'll be done by the routers choice of load-balancing (L3). If you are going to the same POP (or box potentially) you can do MLPPP and have a more effective L2 load balancing.
Otherwise, it's possible to get an iMux DSU (Digital Link is a vendor as I recall, but there may be others) that allow that magical bonding to occur prior to the router seeing the link. At that point, the router just sees a bigger line coming in (some do 6xT-1 and have a 10meg ethernet output to your router). If you're seeing the balancing the way that you are, most likely that vendor (I have no specific knowledge about the A-vendor) is doing usage-based aggregation which isn't exactly a balancing act. The ones at some of my sites are MLPPP which is a vendor-agnostic approach for the most part. Scott -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Elijah Savage Sent: Tuesday, January 24, 2006 7:28 PM To: Matt Bazan Cc: nanog@merit.edu Subject: Re: T1 bonding -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Matt Bazan wrote: > Can someone shed some technical light on the details of how two T1's > are bonded (typically). We've got two sets of T's at two different > location with vendor 'X' (name starts w/ an 'A') and it appears that > we're really only getting about 1 full T's worth of bandwidth and > maybe 20% of the second. > > Seems like they're bonded perhaps using destination IP? It's a vendor > managed solution and I need to get some answers faster than they're > coming in. Thanks. > > Matt > More than likely they are not bonded t1's they are just load balanced by the router which by default on Cisco is per session. Meaning pc1 to t1#1, pc2to t1#2, pc3 to t1#1. If they are truly bonded with some sort of MUX for a 3 meg port then you would not see the results you are seeing. - -- http://www.digitalrage.org/ The Information Technology News Center -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFD1sXyt06NWq3hlzkRAvi4AJ0R4RVii+Wrxzs5WI5es+FYhxHD0ACgioFW /UHUMapXnmuPFSpKrXzD3JU= =MqxV -----END PGP SIGNATURE-----