Question

Network: Failover to 2nd ISP

  • 30 July 2016
  • 7 replies
  • 1285 views

Small office with 30 phones - we have a Cisco 5520 firewall configured to failover to a secondary ISP (Different Static IP) if we lose service, the failover happens in 2 seconds -- is there any way to keep phone calls alive if the outgoing IP address changes mid call?


In my testing the phone has a registration problem when the failover occurs


The internet has no issue when the failover happens - videos continue to stream, email works, etc.


7 replies

SIP trunking will drop when the primary connection is lost.  Will need time to re-register on the secondary connection.
Search for BigLeaf. They and some others have specialized SDN appliances designed for redundant voip circuits.
I'll leave this here: http://www.bigleaf.net/overview/
DeanPar, what equipment are you using now as a Failover? we have a couple of offices with Charter/CenturyLink + Verizon, but we have the same problem if the main line goes down, after a couple of seconds the Wireless Verizon line comes up, but the phones need time to re-register... BigLeaf is a 3rd party company providing continuous service ? Interesting... Is the only way to do it ?
Claudio - We failover from one ISP to another ISP (Comcast Cable - Verizon FIOS) - but have issues with the phones. Both ISP connections go into a Cisco Firewall which is setup to monitor the primary connection out to 4.4.2.2 - if the ping echos stop for more than 2 secs we failover - the Firewall senses when the connection is available and reverts back. Currently we are tracking which service is the most reliable and using that as primary... I have not yet looked into BigLeaf - did a little reading and may contact them...

Does anyone know the time required to re-register, willing to sacrifice the existing call but can't wait 10 minutes for the phones to come back on line.


Hello @Brad Johnson, apologies! I highly suggest you create a case for this. You can click HERE, to open a case. Thank you!

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