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Can any one Help me regarding E&M in CISCO by which PSTN line can use

Dear sir I am requesting you to give some time to read my problem what I feel that u can solve this thing …

Now from the very beginning I am telling scenario.

We have 2 office . let give the name of that office one is A and another one is B .

Side A has 4 PSTN connection entered in to the CO port of the PABX system. I request my PBX engineer to configure the PBX system & add & E&M card. & then setup one Cisco 1751 4V it has 2 Ethernet card one is for LAN another one is for WLAN. NM is all E&M. what I did that is I connect that E&M with the PBX system. That means it is a TIE TRUNK.

In the other office that Means in Side B what I Did that is I have another PBX system but in Side B there is no Telephone lines. (PSTN). It is very important that both the office are connected through Radio Link .. & the ping time between them is 10ms/13ms/20ms.

Now my PBX engineer configure the E&M card of the PBX in side B then I connect that with my another Router which is for SIDE B this router is same like SIDE B .

Previously I did not mention that from the Radio Link is connected with the Router in both side & the LAN port is connected with the switch.

Thing is when side A want to call side B then they press 82 to get access the Router E&M Port then they Press Side B router Destination Pattern 7(I assigned that according with my PBX engineer ) then any 3 digit like 111 then it is ringing .. & both the person can talk & the voice quality is also good.

Now when the Side B people want to talk SIDE A ppl then what they do they dial 9 to get access to their router E&M Port then dial the Side A router destination Pattern like 5 (which is given by my PBX engineer.) & dial any 3 digit like 115 . then it is ringing.

Up to this much is ok .. But my problem is some where else.

That is the SIDE B people want to use the PSTN line which is connected with the PBX of Side A. one more thing I forgot to tell that the People in side A when they want to get access to PSTN or dial the PSTN network then they dial 9 to get access . then they got a dial tone which is PSTN dial tone after that they press the PSTN number.

Now when the SIDE B ppl dial 9 then they get access the dial tone of his own router which is connected with that PBX system. Then they press 5 to reach side A then usually they can press the 9 & the PSTN digit …but it is not going… what can be the problem . is the problem in my configuration or with the PBX system or this is the limitation in the E&M card of the router.

I am in very big problem for this reason.. so will u kindly help me for this .. & I am very glad to u that u read this with ur full passion.. & I request u to help me if u can.




Re: Can any one Help me regarding E&M in CISCO by which PSTN lin

Since there has been no response to your post, it appears to be either too complex or too rare an issue for other forum members to assist you. If you don't get a suitable response to your post, you may wish to review our resources at the online Technical Assistance Center ( or speak with a TAC engineer. You can open a TAC case online at

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.

New Member

Re: Can any one Help me regarding E&M in CISCO by which PSTN lin

Hi Minhaz

This should not be a problem, as I have done the exact same thing, just my offices was in Singapora and Beijing, and my routers were 2600, but its no big deal.

To me it looks like digits manipulation and routing, but its very hard to check before seing the configurations.

could you post the configurations ?, or send them to my private email:

Is there a PSTN line at site B, or are they supposed to use the side A PSTN ?

Can you reveal the local extensions numbers used at site A and B ?

/Rene Bo