MikroTik to Cisco site to site VPN tunnel

I have a site to site VPN tunnel set up between a Cisco 2811 router and a Mikotik RB 800.

I have two problems with the tunnel. First, the tunnel sometimes drops and I only seem to be able to get it back up by initiating some traffic from the Cisco side. I am running keepalives on the Cisco but this doesn’t seem to do anything. I am keeping the tunnel up now by constantly pinging a remote host but I would like a better solution.

Second, I have a Panasonic IP phone connected on the Mikrotik side of the tunnel. I can ping the PBX on the Cisco end of the tunnel & the phone gets a dial tone and is able to place calls. However, no one is able to hear me, although I can hear them. I tested the phone over our local network and it works fine, it just has problems at the remote site.

As for the IP phone: when the call connects, all traffic is sent via UDP. Make sure you aren’t natting this traffic otherwise you will get unidirectional traffic. Also, double check your firewall rules.