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New Member

Connecting routers back-to-back over large distances

We have a requirement to connect two Cisco routers (Point-to-point) across our fibre network.

We don't want to use any WAN equipment in between. We can use both E1s and STM-1s for this connection.

Can anyone tell me what interface types (port adaptors) will support this configuration? (DTE to DTE)

I would ideally like to use ATM-E1 cards for this connection, but I beleive layer 2 protocls require DCE WAN equipment inbetween.

(Are we soley restricted to Packet over SONET for this configuration type?)

New Member

Re: Connecting routers back-to-back over large distances

I must admit that I am totally mystified by your requirements.

However, I can answer some of your questions.

An ATM T-1 or E-1 can be used without an ATM switch in a back to back configuration. Without a switch, there will not be any signaling. Lack of signaling implies no LANE, No SVC's and no detection of down circuits. What can be run is one or Multiple PVC's and/or CLIP (RFC1577). In this case you "must" run a routing protocol across the link to detect circuit problems.

This works whether the T-1 / E-1 is a foot long crossover or through transport across campus or across the country.



New Member

Re: Connecting routers back-to-back over large distances


Thanks for the reply - very useful. This connection is only going to be used for two single point to point links (2 pair of routers) across existing bandwith we have with another company. There is no WAN equipment at their end, and we won't have future requirements for different routers being added in.

We'll be running EBGP between the end points, and HSRP interface detection for failed links. i.e. only one pair of routers is actively sending data at ant one time.

I've also been recommended E1 VWIC cards-G703...rather than have to use ATM.