Mikrotik router as NAT gateway with Cisco 8861 IP phone issue with regular voice drops for about 10 seconds

RouterOS General
1

Hello, I need to configure a Mikrotik AX3 with routerOS7 in a local LAN network that contains Cisco IP phones. The phones being used are Cisco CP 8861 IP phones and should connect to external cloud sip provider.

The phones connect no issue with the call and registration, but approximately every few minutes or so, the call stays connected, but no sound is heard for about 10 seconds, then it resumes. The call is not dropped completely.

I am not a SIP/IP phone expert.

I have tried setting udp timeout 30seconds and stream-timeout to 10minutes, disabled sip alg.

Your assistance would be greatly appreciated to help resolve this call issue.

Thank you.

2

Maybe you have to enable the NAT helpers and/or play a little bit with them? They're located in /ip firewall service-ports

1 Like
3

Thank you for your quick response. I was onsite today and found there was a network loop, ie 2 cables connected to the same switch and it was causing the loop as the MT could see its own MAC address in the arp table. Isolating the switch, etc resolved it and didn’t drop for 5 minutes. It seems that the network loop issue did not affect the Cisco (Meraki) device’s audio stream, faster processor or better handling perhaps.

Thank you