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Jose Reyes
Cisco Employee
Cisco Employee






AT&T SIP Trunking Information

Introduction: SIP or H.323 trunks are the most common VoIP trunks deployed today to interconnect to the outside world (i.e. the Public Switched Telephone Network / PSTN) or to talk between IP PBXes (such as between UC500s at multiple sites). The UC500 supports standards based SIP or H.323 trunks. SIP trunks are the most popular choice today as an IP based PSTN interconnect for a variety of reasons.To make SIP Trunk deployments to UC500 simpler, the CCA tool provides a drop down with a list which includes AT&T IP FlexReach service which has been interop tested and included within the CCA 1.8 tool.

Below are a number of links to help you undestand how to configure the UC500 to work with AT&T's FlexReach Service.


UC520 sample config for AT&T FlexReach
Cisco Unified Communications 500 Series SIP Trunking Configuration Guide for AT&T IP Flexible Reach Service
Overview of SIP Trunking and SBCS
SBCS Partner webinar on SIP Trunking


Practice lab goes over how to configure a UC500 in PBX mode doing SIP Trunking. This does require another UC500 or some other device to simulate the SIP Trunk. SBCS Practice Labs: First Look Lab #3
Questions asked on the Configuring SIP Trunking SBCS Webinar Click here to see the questions and Answers
SBCS Videos: Configuring UC500 for for Generic SIP Trunk provider (VOD)




Useful Technical Links

CUCM Software Compatibility Matrix: CUCM Software Compatibility Matrix
Cisco Tech Forums:
Cisco Tools:
UC Test Matrix and System Release Information: UC 4.x and below        UC 5.x and above
Cisco UC500 and AT&T Flexreach Service link: UC500 SIP Configuration Page
UC QuickStart training:
Cisco Partner Central Unified Communication Website:
UCSBCS (UC500 website):
Cisco Campaign Builder:
Customized Partner Intelligence Newsletter:
Steps to Success:
Cisco Partner Central Unified Communication Website:
Cisco CallManager Capacity Tool (CCMCT):
IPC Voice Tools:
Solution Expert tool:
Quote Builder tool:
The Cisco Product Advisor: Cisco Product Advisor
Cisco Product and services URL:
Cisco Feature Navigator:
Cisco ConfigMaker Software:
IP Subnet Calculator:
VoIP bandwidth calculator:
Erlang Calculator:

CUEAC Training Videos for AT&T Engineers:

Training and Labs

Cisco E-Learning Connection:
First Look Lab on UC500 in PBX mode doing SIP Trunking:


Cisco AT&T Go-to-Market Portal

AT&T Go-to-Market Portal


How to get Cisco support via phone

Cisco Presales Number: 800-553-6387
Cisco TAC Number: 800-553-2447


How to open a Cisco case for support via the web

PRH (Partner Resale Help) Desk
The PRH Desk is available Monday through Friday, 7AM – 6 PM Worldwide Monday thru Friday
Call 1-800-553-6387, option 1, option 2, option 2 , option 6


PDI Help Desk - Cisco Unified Communications
The PDI Help Desk is a support resources page allows you to search our knowledgebase for information about planning, design, and implementation of Cisco Unified Communications products and technologies.


Cisco TAC Website
Open a TAC case on-line

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