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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Group:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">I am trying to complete a conversion from Acme Packet/Oracle SBC to Metaswitch Perimeta SBC. We found late during the cutover process that Polycom/Metaswitch
hasn’t implemented a common TCP strategy to keep firewall TCP sessions/connections alive. Has anyone in the group successfully implemented a TCP strategy and if so, am I missing anything?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">With the ACME topology, all phones do the following regardless of protocol to maintain pinholes through firewalls:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">1 SEC Phone -> Register -> Firewall -> SBC -> Register -> Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">1 SEC Phone <- Register (expire 60 Seconds) <- Firewall <- SBC <- Register (Expire 1 Hour) <- Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">60 SEC Phone -> Register -> Firewall -> SBC<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">60 SEC Phone <- Register (expire 60 Seconds) <- Firewall <- SBC
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Polycom: Requires use to frequent SIP registration (maintained by Perimeta) to keep SIP pinholes through firewalls alive.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Metaswtich: Requires TCP clients (Polycom) to maintain pinholes using native TCP keepalive syn/ack messages.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Polycom’s implementation of “TCP keepalives” is only applicable if the phone is using TLS. There is no such setting for non-tls TCP based traffic. So the phone
will establish a TCP connection to the SBC, and then site dormant if no registration/call/subscription messages traverse. The firewall will close its ports, and the phone will lose connectivity.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Metaswitch has a fast-nat feature, which is used to shield switches from UDP based registrations. When enabled, fast-nat modifies the endpoint expire timer to
allow the endpoint to re-register (keeping the firewall session alive). For UDP, this works correctly, and the SBC responds to the endpoint with a 200OK. But for TCP, the SBC passes the re-registration attempt back to the switch.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">TCP Metaswitch Example with fast-nat:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">1 SEC Phone -> Register-> Firewall -> SBC -> Register -> Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">1 SEC Phone <- Register (expire 60 Seconds) <- Firewall <- SBC <- Register (Expire 1 Hour) <- Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">60 SEC Phone -> Register-> Firewall -> SBC -> Register -> Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">60 SEC Phone <- Register (expire 60 Seconds) <- Firewall <- SBC <- Register (Expire 1 Hour) <- Broadsoft
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">My question to the group, is has anyone implemented TCP based registration using Perimeta and Broadsoft?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Dave<o:p></o:p></span></p>
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