Multiple VLANs and SIP-based VoIP-incoming calls not working

RouterOS General
1

I have created multiple VLANs on my RB600’s ethernet port that connects to my LAN: 30 for VoIP, 40 for Data/Internet.

These IDs are tagged and passed through my various switches to my end users’ CPEs.

The CPEs are SIP-based VoIP gateways. I have input the proper settings for making and receiving calls (based on a remote softswitch) as I have done in other NON-VLAN installations. I have also input the proper VLAN tags in the CPE for VoIP and Data packets.

My problem is: my users can ACCEPT calls and both parties can hear each other, but when my users MAKE calls out, the calls connect but the receiving party can’t hear anything. The user, however, can hear the receiving party.

I believe this is all related to the VLAN setup, because if I connect the same setup directly to my Mikrotik on a non-VLANed port everything works fine. While it could be the VLAN settings in the CPE, I want to be sure it is NOT the VLAN settings in my Mikrotik.

Has anyone done and experienced anything similar to this and figured it out? I’m installing Wireshark to see if I can trace the packets when a call is made, but this is driving me nuts.

2

I was able to solve part of my problem by turning off the h323 and sip Service Ports under /ip firewall. That fixed the issue with the softphone on my laptop.

Now my only issue is getting my hardware SIP devices to be able to provision themselves. I’m sure it’s a routing issue, as a syslog dump of my test SIP device indicates that it can’t resolve DNS. I entered the IP address of the provisioning server, but then it isn’t able to call out to THAT address. Routing to be sure…

3

This turned out to be NAT / routing issue. Our vendor pushed a certain network design onto us, which in turn limited Internet access to our CPE devices, meaning they couldn’t properly navigate the routes to the SIP softswitch in the outside world. I simplified their design by having the CPEs get their IP addresses from our router and they then had a direct route to the Internet through one NAT translation. Worked like a charm.