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<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Back in the Day we had 11 Nortel PBX’s. I think that we had 11 PRI’s registered as MGCP. I don’t think we ever got the PRI’s to drop
calls when a phone was transferred back to CUCM. Our next step was to look at SIP, but it just was not worth the cost to put a SIP trunk on the Nortel PBX to solve our issues (was like $30,000 or $40,000 to do so)<o:p></o:p></span></a></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Best thing we do was purchase more CISCO phones :>
<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thank You,<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Neal Haas<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">NSE, Communications<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><i><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Please report Troubles to the Help Desk. 559-600-5900<o:p></o:p></span></i></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Telephone (559) 600-5890<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> cisco-voip [mailto:cisco-voip-bounces@puck.nether.net]
<b>On Behalf Of </b>Anthony Holloway<br>
<b>Sent:</b> Tuesday, March 7, 2017 2:54 PM<br>
<b>To:</b> Cisco VoIP Group <cisco-voip@puck.nether.net><br>
<b>Subject:</b> [cisco-voip] Anti-Tromboning Tie Lines to PBX<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I'm not sure how often this gets configured out in the wild, but I do know that there are few different flavors of this feature, depending on your scenario. E.g.,
<a href="http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/media-path.html#concept_674530029296875008039300537109374">
CUBE Media Anti-Tromboning</a><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The one I'm interested in would involve a tie line to a legacy PBX, and I'm not married to the IP technology: SIP, H323, MGCP, whichever will get the job done.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">CUCM ---IP---> VGW ---T1/PRI---> PBX<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The call scenario I'd like to see if we can avoid is when a call is established from CUCM to the other PBX, and then a phone on the far side transfers the call to an IP Phone on the CUCM side, I'd like the PRI usage to drop to 0 trunks
in use, instead of nailing up 2 trunks for the duration of that call.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I'm looking for your experience and feedback in configuring anti-tromboning in this scenario. One of the hardest parts in researching this, is knowing what terms to search for. I think I've narrowed down the terminology to QSIG Path Replacement,
<a href="http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/8_5_1/ccmsys/accm-851-cm/a08procl.html#wp1156114">
as described in the CUCM SRND</a>.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Though, without real-world working experience, it's hard to know if I'm right or not.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">So, I know there's some good legacy telco knowledge out on this list. What do you know? Thanks!<o:p></o:p></p>
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