Cabling 2 ISDN interfaces

qaadir10211

HI All. I have 2 2524 routers with ISDN NT1 interfaces in each. Is there a way that I can cable these together to emulate an actual ISDN WAN connection?

tunerX

I know it is possible with voice ISDN interfaces, if your 2524 supports voice calls and cane emulate layer 1 and supply line voltage then you could do it.

You set up two voice NT1 interfaces as network side with the "isdn layer1-emulate network" command. You then plug in two routers with S/T interfaces. This requires 4 interfaces. 2x NT interfaces on your ISDN switch (router) and 2x S/T interfaces.

The concept is simple. The router with the NT interface emulates the network and you route the D channel via x25 to the different BRI ports. You then map x25 NSAP addresses to each BRI port. The switch will route the ISDN to the two routers with S/T interfaces.

I do not think that you can do it with a strict back to back connection. The voice cards are usually expensive and cost far more than a two port ISDN simulator.

routerA-S/T-NT1-RouterSwitch-NT1-S/T-routerB

interface BRI 0/0
no ip address
isdn switch-type basic-net3
isdn protocol-emulate network
isdn layer1-emulate network
isdn incoming-voice voice
line-power

interface BRI 0/1
no ip address
isdn switch-type basic-net3
isdn protocol-emulate network
isdn layer1-emulate network
isdn incoming-voice voice
line-power

interface BRI 0/0:0
no ip address
ip mtu 1514
no ip mroute-cache
x25 address 1001000
clns mtu 1514
!
interface BRI 0/1:0
no ip address
ip mtu 1514
no ip mroute-cache
x25 address 2002000
clns mtu 1514

x25 route 2002001 interface BRI 0/1:0
x25 route 1001001 interface BRI 0/0:0


The cost of the