Bad video quality on VPN but good quality on MRA

[sysadmin5]

Setup :

Data Center

• CMS1000 2.4
• CUCM 11.5
• Expressway C & E 12.5
• CMS Recorder & Uploader

Branch A

• 1 Room kit mini
• Connects to DC via SSL VPN on Sonicwall Firewall. Dedicated 50 Mb internet pipe for Video conference traffic only.
• No ports blocked & no policy applied.

Branch B

• 1 Room kit mini
• Connects to DC via SSL VPN on Sonicwall Firewall. Dedicated 50 Mb internet pipe for Video conference traffic only.
• No ports blocked & no policy applied.

We are doing a demo with one Room kit only & will increase the endpoints on project completion.

Branch A & Branch B dials the Space ID and gets connected in a conference call on CMS server in DC. Call quality is good but not perfect, picture breaks on movement. Packet loss is less then 1%. Call rate set to 1024 Kbps

When Branch A dials Branch B directly, call quality is perfect. Call rate set to 1024 Kbps

When we disable VPN tunnel and use same internet to register Endpoints via MRA, over Expressways, video quality is perfect.

Please suggest how to make this work on VPN, as we dont want to use it via MRA becuase TMS dont supports Collab Edge devices & we tend to register all endpoints via VPN only not MRA.

[Wayne DeNardi]

At a guess you're probably having issues with the MTU.  Using a VPN, the MTU is going to be a lot smaller than what is likely configured on your endpoint.  Try setting the endpoint to a smaller MTU size (like 1392 instead of the default 1500).

[sysadmin5]

I tried but it didnt made any difference.

Working with TAC now, surprisingly he is saying 1% packet loss will degrade the video quality & I told him Room kits are designed for Cloud registrations & over internet 1% packet loss is minimal, then how can you prove your statement. Waiting for his response.

ANy other settings I can look for ?

I noticed under CMS Call settings, there is bandwidth settings for VPN, what is it for ?? can tweaking this makes any difference ??

[sysadmin5]

ANy help please.

I am still struggling with this issue.

[gariusmar · Accepted solution]

Hi,

We have the same problem with VPN and CMS we set the MTU on CMS to 1300 and the video and sharing quality was much better than before. Now we  migrated our CMS and Expressway`s to the latest software. Since the upgrade, Expressway-C (MTU 1500) and CMS (MTU 1300) can only do signaling, media is unable to connect. If I set the Expressway`s MTU also to 1300  it works for CMS but the Telepresence endpoints cannot send and recieve media for B2B communication.

Could somone help me ? I do not understand wy is it working on the old environment.

Thanks