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Degraded VoIP quality over Easy VPN

Hi All,

I've established a hub (Cisco 1921-G2) n spoke (Cisco 887VA) Easy VPN environment using network extension mode. The VPNs are configured to carry data and Voice traffic.

I've got separate VLAN on the HUB for data (vlan 1) and voice (vlan 10) and allowed traffic from both VLANs over Easy VPN tunnel. VPN establish without any issue and works fine for Data but for voice remote user can hear other caller just fine but his voice to the other end gets jitters and not clear. (Especially when we are running uploads: Found out during DSL speed test)

On the remote user end (Spoke- Cisco 887-VA) Avaya IP phones, point direct to VLAN 10 on Hub via IP network. But the internal LAN IP of the phone is allocated via local Cisco 887-VA DHCP.  I've implemented outbound QoS on Virtual-Template 1 VPN interface but it has not helped

Our remote users have only ADSL lines with appox 10Mbps download and 0.8 Mbps upload. I know its not ideal but if there is something I can do to increase the VoIP call quality.

Shall I create a sperate VLAN on the spoke routers as well for IP phone? And allow both VLANs from Spoke through VPN to communicate with HUB. I've given this a try before but it didn't helped and then I tried QoS. Shall I try voice VLAN and QoS both at the same time now?

If there is any spefic QoS you would like me to add, please let me know.

I've already adjected the tcp mss to 1356 on VLAN 1, shall I apply it on any other interface as well?

The command, "sh crypto ipsec sa" shows MTU as 1500, do I need to decrease ths MTU size here?

I've included the config of the spoke router, if any one want to have a look in case.



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