Showing results for 
Search instead for 
Did you mean: 

ISDN gw 3241 version 2.x

Isabel Mari Berg


I wonder if it’s possible to show the source E164 alias as the calling no on an ISDN endpoint with traffic going through the ISDN gw? And, the other way around, is it possible to show the source ISDN no as the calling no on a H323 endpoint, going through the ISDN gw?

In order for this to work the ISDN gw would have to be able to keep the source address when translating from one protocol to the other and send this as the source no instead of its own.

I’ve read the “getting started guide” but found nothing about this subject.



Patrick Pettit
Cisco Employee
Cisco Employee

HI Isabel.  If I understand your inquiry correctly here, on an IP to ISDN call, you want to show the E164 alias of the IP system on the ISDN System? 

If you have "Send Calling Party Number To ISDN Network" set to Numeric Only, then the GW will send the calling party number to the network as your E164 alias on the system.  The H323 system must have an alias assigned to it for the H323 side to work, but..the kicker here is, if the ISDN carrier removes or doesn't send this to the far end ISDN system, then it won't be displayed as such.  You have to be sure your ISDN carrier will pick up the calling party number and send that along to the far end sytem your connecting to on the ISDN network. 

For the opposite direction, the carrier may or may not send the calling party number to the GW, and thus the call will show up as originating from the ISDN GW on the H323 leg of the call, and not the actual number from the ISDN side. 

But first, I'd double check your setting to see if you are sending the calling party number to the ISDN network, and hopefully the carrier is picking this up to send to the ISDN system as well. 

Let us know what you find out. 



Martin Koch

Hei Isabel :-)

Do you use the public ISDN to transmit the calls?

In addition to what Patrick said, you find the "Send Calling Party" parameter in Home > Settings > ISDN.

Think Always is enabled by default and as long as calls get placed it should be fine as well.

What are the e164 numbers, are this the real subscriber numbers? If not the phone provider might

overwrite it or you get a non routable number shown on the remote side.

So if the public phone number is 12345678 also the e164 number shall be 12345678.

Besides findme (which can become handy here as well as it supports a outbound e164 number)

I am not aware that the VCS or the ISDN-GW could rewrite the source number so it fits what the

telephony provider wants to see.

From what I have seen on ISDN to H323 calls the ISDN GW will populate the e164 number field

with the isdn number and the h323id with the configured h323-alias of the isdn gw.

The things like "include prefix" setting, interworking and findme will also change the behavior.

It will also depend on what the destination endpoint will show, h323-id which is the first source

alias, the e164 number or both.

Give me a call if you need more input.

Please remember to rate helpful responses and identify

Isabel Mari Berg


Thank you so much, both of you.

I'll try out your suggestions next week when i have access to the isdn gw and I'll let you know.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: