<div>
<div class="content wysiwyg-content">
I currently have two sites - one with say extensions 56XX and the other with 76XX. 56XX can call 76XX via the WAN with extension. But what if I wanted 56XX to reach 76XX via the PSTN instead - calling the full 916-555-76XX? &nbsp;How can I tell CUCM 10.x to use PSTN instead of using the internal phone-phone extension dialing? <br />
<br />
The background is that I am changing WAN providers and so there is some certainty as to he quality will be. If I get reports of bad call quality I'd like to just have users call via the SIP trunk to PSTN rather than over the WAN as that quality will be good for sure. Thank you.<br />
<br />
I believe part of the answer is AAR. If the WAN goes down I am pretty sure that calls from site A will use AAR info to call out via the PSTN. The question is how can I tell CUCM to prefer the AAR instead of calling the extension via the WAN? Or is that even possible?<br />
<br />
<a href="http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-version-80/113478-aar-config.html" rel="ugc">http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-version-80/113478-aar-config.html</a>
</div>
</div>


I currently have two sites - one with say extensions 56XX and the other with 76XX. 56XX can call 76XX via the WAN with extension. But what if I wanted 56XX to reach 76XX via the PSTN instead - calling the full 916-555-76XX?  How can I tell CUCM 10.x to use PSTN instead of using the internal phone-phone extension dialing? 

The background is that I am changing WAN providers and so there is some certainty as to he quality will be. If I get reports of bad call quality I'd like to just have users call via the SIP trunk to PSTN rather than over the WAN as that quality will be good for sure. Thank you.

I believe part of the answer is AAR. If the WAN goes down I am pretty sure that calls from site A will use AAR info to call out via the PSTN. The question is how can I tell CUCM to prefer the AAR instead of calling the extension via the WAN? Or is that even possible?

http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-version-80/113478-aar-config.html

CIsco UCM route out PSTN instead of over WAN

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.

IP Telephony

Voice over IP (VoIP) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms commonly associated with VoIP are IP telephony, Internet telephony, broadband telephony, and broadband phone service. The term specifically refers to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).  Examples of the VoIP protocols are H.323, Media Gateway Control Protocol (MGCP), Session Initiation Protocol (SIP), H.248 (also known as Media Gateway Control (Megaco)), Real-time Transport Protocol (RTP), Real-time Transport Control Protocol (RTCP), Secure Real-time Transport Protocol (SRTP), Session Description Protocol (SDP), and Inter-Asterisk eXchange (IAX).

Voice Over IP

Cisco PIX is a dedicated hardware firewall appliance; the Cisco Adaptive Security Appliance (ASA) is a firewall and anti-malware security appliance that provides unified threat management and protection the PIX does not. Other Cisco devices and systems include routers, switches, storage networking, wireless and the software and hardware for PIX Firewall Manager (PFM), PIX Device Manager (PDM) and Adaptive Security Device Manager (ASDM).