Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Cisco 2503 ISDN simulation

Hello all,

I want to do a ISDN dial-up connection simulation with two 2503 router WITHOUT actually using Telco ISDN service (i.e. connect both routers via BRI ports with a single CAT 5 cable). I believe if I want to do that I will need to change the pin configuration of the cable as ISDN line uses 4 wires for S/T interface and 2 wires for U interface. Could any one tell me is it possble to test the ISDN connectivity with that method? If it is possible, could you please advise me the cable configuration that I will need to have?

Thanks in advance

New Member

Re: Cisco 2503 ISDN simulation

I don't think what you are trying to achieve is possible with-out some sort of switch in between.

New Member

Re: Cisco 2503 ISDN simulation


It will not work at all. First frame toward network side and Subsriber site (user are not same and State machine on both side are not same.

As the network side state machine is no same twill not able to start any thing. You really need to have a thru network simulator. (ISDN doesn't work as a modem, so

back to back config can't be done). Check I430 for more detail.



New Member

Re: Cisco 2503 ISDN simulation

oh well, if that is the case. I have no other choices other than renting two pairs of ISDN BRI or getting a ISDN simulator. :)

Greatly appreciate for both of the replies.

CreatePlease to create content