Bonding two T1s

Hi folks,
We have a situation where we need to bond two T1s to achieve and
aggregate of 3meg. The routeres are a 3725 and a 1721. Both have
available serial ports for the operation.
I've been looking for an example configuration to help me get it set
up. So far I've found a couple but I don't really understand how it
works. The examples I've seen seem to indicate that the bonded link
won't have IP addresses over the WAN link. Is that correct?
If someone could post a config with some details I'd really appreciate
it.
Thanks.
Jim
Reply to
jhud
Loading thread data ...
PPP multilink
Reply to
Phil Watkins
Right, I got that part. What I'm trying to figure out is how the configuration should be done. Cisco's site shows a couple of configurations, but they don't comment them enough for me to be able to determine whether or not they're what I need.
Reply to
jhud
hmmm, I've forgotten how to do it. I'll have a go now and see if I can get it working, if I do I'll post my config.
Reply to
Phil Watkins
hmmm
formatting link
I'm buggered if I understand it though and haven't got it to work yet.
I see what you mean about no IP address. The example seems to be using briding, not quite sure if that's the only way it can be done. I don't think so really.
Reply to
Phil Watkins
I don't have too much of a problem with it bridging I suppose. I'm more interested in throughput. We have three remote servers there and full BUs have become a W/E long nightmare.
That link is a better example than I'd found so far.
One odd thing on the example. Notice that there's a ppp multi statement on the "shutdown" isdn int? Seems unnecessary.
Reply to
jhud
i know this is a cop-out, but why did you decided to load balance this way rather than through the routing protocol?
Reply to
Phil Watkins
We don't want to load balance, but rather bond them for an improved aggregate throughput. As we understand it (and we may be nuts) bonding the Ts in this manner will not load balance them but logically combine them as a single pipe.
Reply to
jhud
I have found that multilink PPP does load ballance better than a routing protocol will, up to about 3 T1's. Maybe I'm an idiot though.
Here's my config (using VWIC-2MFT-T1 card)
interface Multilink1 ip address 192.168.250.a 255.255.255.252 ppp multilink ppp multilink group 1
interface Serial0/0:0 no ip address encapsulation ppp ppp multilink ppp multilink group 1
interface Serial0/1:0 no ip address encapsulation ppp ppp multilink ppp multilink group 1
of course with this card you have to configure the controller...
controller T1 0/0 framing esf crc-threshold 320 clock source internal linecode b8zs channel-group 0 timeslots 1-24 speed 64 ! controller T1 0/1 framing esf crc-threshold 320 clock source internal linecode b8zs channel-group 0 timeslots 1-24 speed 64
The physical layer config may vary depending on your hardware (WIC-1DSU-T1, WIC-1T, etc.).
Reply to
rfield
thanks for filling me in on the config. I've read similair things about throughput being better with PPP. Would be interested to here how much better.
Reply to
Phil Watkins
int multilink 1 ip add 1.1.1.1 255.255.255.0 encapsulation ppp multilink-group 1 int s0/0 encapsulation ppp multilink-group 1 int s0/1 encapsulation ppp multilink-group 1
Jonathan
Reply to
Jonathan
Hi gents,
Thanks for all the feedback. I think I've got it now.
Jim
Reply to
jhud
Hi folks,
Just got back from putting up the link. Went smooth as silk. Again, thanks for all the help.
Jim
Reply to
jhud

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