Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

CUVC 5230 and CTMS Telepresence Interop Quality

We have recently installed a new CUVC 5230 MCU to interoperate with our existing Telepresence system.

We have conferences up between TP units and VC endpoints but the quality is poor on the Telepresence end, with bad motion and lots of pixalisation (it looks fine on the VC end).  I believe it's due to the MTU settings but I can't find any information on how to change the MTU.  I've checked all the region bandwidth settings, the CTMS, CUVC and VC endpoint are all on the same subnet and their is no network congestion, however we do have an MTU of 1400 on the network.

We previously had a 3515 MCU that experienced issues and changing the MTU on both the MCU and EMP resolved the issue, but I am unsure as how to change the MTU size on the 5230.

Any assistance with this would be much appreciated!


Re: CUVC 5230 and CTMS Telepresence Interop Quality

Hi Nick,

Whats the technical reason that led you to believe this is the problem? Please share with us

CUVC version

CTMS version

CTS version


Here are the instructions:

To change the MTU in EMP

Telnet to the EMP and enter the following case sensitive command:


A list of menu items will appear - select 2 for Configure max MTU size and enter 1300 and
hit return

You will see something like: 
Select: 2
Enter MTU size
<1480>: 1300
setting MTU size to 1300

MTU size was successfully written to CFG file

Close the telnet session and retest and confirm

Let us know

Re: CUVC 5230 and CTMS Telepresence Interop Quality

Thanks for the response.

CUVC version - 7

CTMS version - 1.6

CTS version - 1.6

Topology - Currently, they are all just sitting on the same switch with CUCM as well.  CTMS and CUCM both have an MTU of 1400.

The CTS unit is running of a seperate switch in the same building.  Non-interop multipoint calls work fine on the CTMS.

When initially configuring the CUVC 5230 I was asked to specify 2 x IP addresses - is one of these the EMP?  If not, how do  I specify the EMP address?

I have experience with the 3515 (but it was an existing installation) and I have used the printCfgMenu command on there before.  When I telnet to either of the addresses I specified when configuring the 5230 and login, it doesn't take the printCfgMenu command and says "C interp: unkown symbol name printCfgMenu".

I suspect that this means I have actually telneted to the MCU rather than the EMP, which leads me to believe I may yet still need to perform configuraiton on the EMP.  How do I set the EMP's IP address?


Re: CUVC 5230 and CTMS Telepresence Interop Quality

CCO is your friend:

Use the console connection to EMP with the following command:


Try that, it will bring up the config menu and select N for netowork settings.

Re: CUVC 5230 and CTMS Telepresence Interop Quality

Awesome thanks - I couldn't find documentation on how to do it with a 5000 series, I dind't think of checking it for the 3000 series as they would be the same.


- Nick


Re: CUVC 5230 and CTMS Telepresence Interop Quality


Re: CUVC 5230 and CTMS Telepresence Interop Quality

Unfortunately I could not get this to work.

From the console (or a telnet session), I couldn't input any commands at all - it would just bring up the menu based interface, allowing me to change network settings, passwords etc.  It seems that the 5230 is indeed different to the 3545.

The network settings didn't have an option for MTU - only for IP, DNS, domain etc.  I checked all other options and couldn't find anything.


Re: CUVC 5230 and CTMS Telepresence Interop Quality

yeah we dont have that documented in CCO for CUVC 5230

Will check tomorrow at the office and will let you know


Re: CUVC 5230 and CTMS Telepresence Interop Quality


I've checked the 5230 configuration guide, install guide and CTMS design guide (which details the steps you need to take on the 5230 to get it to interoperate with Telepresence) but couldn't find any reference to MTU size on the 5230 anywhere.

Re: CUVC 5230 and CTMS Telepresence Interop Quality

I found how to do it......

In the GUI of the 5230, go to Advanced Parameters -> CLI

Enter the following command:

Command: SetMTUsize

Parameters: [leave blank]

value: 1400 [or whatever you want to set the MTU to]

Changing the MTU to 1400 (to match the CTMS) helped, but there is still allot of ghosting/pixalisation.  Regular CTMS meetings work fine.

Any other ideas?


Re: CUVC 5230 and CTMS Telepresence Interop Quality

Hi Nick,

Can you include exact version for all components

Include topology and LAN switches model you are using

Do you have any TP eP in the Local LAN

Please provide all details as possible

we had a history of 2 cases with CUVC similar problems and turned out to be a LAN issue


Re: CUVC 5230 and CTMS Telepresence Interop Quality

CTS-1000 - Connected to a 3750-24-FS (100Mbps) <- subnet has an MTU of 1400

3750 connects to a 6500 (1Gbps)

6500 connects to a 3750G-24TS (1Gbps) , which connects to the CTMS and 5230.

The CTMS and 5230 are on the same subnet, the CTS-1000 is on a different subnet.  All subnets are terminated on the 6500.

Other traffic on the LAN is negligable at the time of testing.  All Telepresence only calls, either point-to-point or multi-point work perfectly.

I have checked all switch ports in the network path for errors and haven't had any.

I did mess around with different MTU sizes on the CTMS, CTS endpoint and CUVC.  Setting it to 1400 on all devices seemed to give the best results but it's still quite bad.

It should also be noted that the CTMS has allot of errors saying "CTMS_ALARM_MEDIA_TOO_MANY_CUVC_INFO" whenever I conduct a test.



Re: CUVC 5230 and CTMS Telepresence Interop Quality

What is the exact version for CUVC?

During testing I have seen that error

during interop calls on CTMS when CUVC is sending IDR requests at the rate of 1 per second.

Changing CUVC version to resolved the issue.
Not sure if its related, if needed please open a TAC case with us for better assistance

Re: CUVC 5230 and CTMS Telepresence Interop Quality

I just got it working by doing exactly that before you replied

An issue I had was that I was unable to locate the software for the 5230.  I opened a TAC case and got a link, upgraded and it all seems fine now.

Thanks for your help.