two isp T1 links with different networks


we have a branch office with 2 T1 links , one being used for voip traffic and other one for data

since the branch office has grown it seems the bandwidth its sufficient.

Hence I am thinking of bonding the two T1 links together BUT

the way there are setup is not a T1 link would be provided to the customer , I mean the ISP's have their routers on site connected to the T1 and then from there each ISP has given us a Ethernet connection to our router.

On our router we simple router traffic based on destination


DATA = - ISP 1

Voice = - ISP 2

Question is how can I bond these two together to have T1 (1.5) + T1(1.5) = 3

let me know if I make sense and which method to use

I have in the past configured Multilink on the routers but that would mean terminating the T1 on the router and using ppp on each side

one more thing that both the above networks are reachable from the head office

If I trace DATA network I end up going from one ISP T1 and if Voice network I end up going from second ISP T1.

From DATA and VOICE I can access the Head Office


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Robert Sutton JrConnect With a Mentor Senior Network ManagerCommented:
I don't see you bonding these if all you are getting is 2 separate ethernet hand-offs without utilizing an MFT card and terminating those two t1's directly on that card.

On another note: Have you verified your QOS settings to see if that helps with your issue?
Fred MarshallPrincipalCommented:
Isn't T1 slow and expensive?  ...

I shouldn't think that the communication mode would care what the subnets are.  But then, I don't use T1s.

A lot depends on your router equipment.
For example a Cisco Small Bus. RV0xx router has dual WAN and can be set for Load Balancing.  That would be an example of what it appears you want.
And, you can tie protocols to a WAN if you like. etc.
lomareeAuthor Commented:
for our router its a 2911 with voice cards FXO in it for VoIP

what do you mean the tie protocols to a WAN ?

Fred MarshallPrincipalCommented:
what do you mean the tie protocols to a WAN ?
The Cisco RV0xx has dual WAN and two modes: Load Balancing and Failover.
I've used both and pretty much have decided that Failover (which switches between the WAN ports)  isn't really better than Load Balancing (which shares the load between the WANs).  Actually, I found some issues with the switching actions.

In Load Balancing mode, you can tell the router (for example) to run all https traffic through WAN1.  That's tying a protocol to a WAN.  So, you could have voice on one WAN and https on the other WAN and everything else shared between the WANs.

I don't think these features are at all uncommon if a device has a dual (or more) WAN capability.
lomareeAuthor Commented:

that's what I wanted to know as that is what I thought too, can't be done

I have not looked into the QoS setting.

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