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On the router, run Debug ISDN Q931, make the call in question and post results.
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On the router, run Debug ISDN Q931, make the call in question and post results.

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Hi<br />
we have configured h323 Gatway.<br />
<br />
when we call landline number 3175 IP Phone to 61871111 and 6187100 are working fine. but other all landline number eg 61871324 and 62300192 etc unable to connect getting busy tone.
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Hi
we have configured h323 Gatway.

when we call landline number 3175 IP Phone to 61871111 and 6187100 are working fine. but other all landline number eg 61871324 and 62300192 etc unable to connect getting busy tone.

Call from cucm to ISDN Failed using h323

IP telephony (Internet Protocol telephony) is a general term for the technologies that use the Internet Protocol's packet-switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit-switched connections of the public switched telephone network (PSTN). Using the Internet, calls travel as packets of data on shared lines, avoiding the tolls of the PSTN. The challenge in IP telephony is to deliver the voice, fax, or video packets in a dependable flow to the user.