Hi,
I’ve got two RB750 to stablish a GRE tunnel and have VoIP traffic between two sites. All the path is controlled by me, having three wifi links between the routers. Everything mostly works, but I find that GRE tunnel is introducing a lot of jitter in the traffic, which is bad for VoIP.
I made a simple test: simultaneously ping to the external IP address and another internal IP, so I have a ping going though the tunnel and another outside. This are the results:
TUNNELED: sent=217 received=216 packet-loss=0% min-rtt=9ms avg-rtt=62ms max-rtt=206ms
NO TUNNEL: sent=210 received=210 packet-loss=0% min-rtt=7ms avg-rtt=26ms max-rtt=70ms
This pings were done simultaneously, so there is no difference in the surrounding conditions or any extra problems introduced by the path. Ping is little, so we can discard MTU problems. The links at both sides were idle except for the pings.
This differences are very important… too much to become unnoticed. The 206 ms max-rtt is specially bad for VoIP.
Any idea on how to improve this tunnel? BTW, 5.22 on both sides.