Hello,
OpenVPN ethernet bridge is set up, to join two segments of the same subnet. All external Internet traffic is routed through a single gateway, serving as OpenVPN server part as well.
Let's name the gateway segment, where all the actual access to Internet is routed to, 'main' segment, and the one connected via a bridge, 'auxiliary' segment.
In general, everything works fine. However, there's problem with Skype traffic, namely:
When VoIP session across segments happens (one person's Skype is working from 'auxiliary', the other from 'main' or outer world):
- users in 'auxiliary' segment report incoming audiostream degraded (poor quality)
- the parties those users talk to notice no degradation at all
When two persons residing inside 'auxiliary' engage in Skype VoIP session, no degradation occurs on either side.
The problem as I see it that in case of Skype a significant part of its UDP traffic bound into 'auxiliary' gets lost. No traffic filtering/throttling is set up on the OpenVPN server computer.
Could someone suggest where to look for possible problems? Other UDP traffic, as I can see using WireShark/other monitoring seems to pass without problems.
The configuration, if of importance, is below.
Thanks.
Server ('main'):
port 1194
proto udp
dev tap0
ca /etc/pki/openvpn/ca.crt
cert /etc/pki/openvpn/server.crt
key /etc/pki/openvpn/server.key
dh /etc/pki/openvpn/dh1024.pem
server-bridge 10.x.x.200 255.255.255.0 10.x.x.245 10.x.x.247
ifconfig-pool-persist ipp.txt
keepalive 10 120
cipher BF-CBC
comp-lzo
user openvpn
group openvpn
persist-key
persist-tun
status /var/log/openvpn/openvpn-status.log
log /var/log/openvpn/openvpn.log
verb 4
Client ('auxiliary'):
client
dev tap0
proto udp
remote 80.66.xx.xx 1194
resolv-retry infinite
nobind
user openvpn
group openvpn
persist-key
persist-tun
ca /etc/pki/openvpn/ca.crt
cert /etc/pki/openvpn/vpn-cc.crt
key /etc/pki/openvpn/vpn-cc.key
ns-cert-type server
cipher BF-CBC
comp-lzo
log /var/log/openvpn/openvpn.log
verb 4
