Re: Media Resources between Router and CallManager?

Matthew Martin · ‎08-28-2015

Hello All,

We have a couple of Cisco 2821 series routers being used as H.323 Gateways registered to CallManager. The 2821s have CFB and TC media resources on them. If I check the status of these resources on the router in IOS, they are both showing as REGISTERED.

But, if I go to the page: CallManager >> Media Resources >> Transcoders, and I list all of the TCs, I can see that the Transcoder resource for each of these 2821s is showing with an Unknown status and Unknown IP Address. However, some 1861 routers that we have, also have similar media resources (*CFB and TC) and these are showing as REGISTERED in both IOS and CallManager. So what is it about these three 2821 routers for why this is happening...

I am confused as to why the router is showing them as Registered but CallManager is showing them as Unknown.

Rtr-2821-01# show media resource status
Resource Providers:

Resource Provider ID :: FLEX_DSPRM Status :: REGISTERED
Service Profiles
MTP ::
TRANSCODING :: 2
CONFERENCING :: 1
Applications :
Application ID : SCCP, Status : REGISTERED

CallManager: Version 8.6.2.24901-1
2821 IOS: Version 15.1(4)M5

Does anybody have any idea about this?

Thanks in Advance,
Matt

Manish Gogna · ‎08-28-2015

Hi Matt,

Can you provide the output of "show sccp" from the 2821 gateways and also share screenshot of the transcoder from cucm page where it shows unknown.

If you do a "show sccp conn" on these gateways , are you actually able to see any active calls using these resources?

If the calls do show up on the gateway then the issue could be cosmetic as far as status of transcoder on cucm is concerned, you can try resetting the transcoder and restarting the RIS Data Collector service from Cisco Unified serviceability.

Manish

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Matthew Martin · ‎09-15-2015

Hey Guys, thanks for the replies!

I apologize for the long delay in replying to your comments. Got stuck dealing with a bunch of other phone system issues the last 2 weeks...

So I was in the process of getting you guys the output of show sccp on the 2821 Gateways and then I went to get you a screenshot of the Transcoder devices from those gateways in: CallManager >> Media Resources >> Transcoders, and when I went to Transcoders the ones for the 2821s are suddenly showing as Registered... Weird!
We upgraded the Router's IOS versions a little while back on these 2821s and I'm trying to remember when we did that, and if it was before/after I noticed these Gateway's Trancoders were NOT showing as Registered...

Is there a command to show when an upgrade took place or when the boot image changed, etc...?

Also, I attempted a Test call (*from cell phone not a fax machine, if that makes a difference?) to one of these 2821s to try the show sccp connections command. And while the call was still in progress I kept running that command, but no connections were showing... See below

2821-Rtr01#
2821-Rtr01#show sccp conn

Total number of active session(s) 0, and connection(s) 0

2821-Rtr01#show voice call st
CallID   CID      ccVdb     Port   Slot/DSP:Ch  Called #   Codec    MLPP Dial-peers
0xD06B   2364   0x4997D370  2/0/6     0/1:1      *9999     14400    99999/1234
1 active call found

2821-Rtr01#

Since the "show sccp" command did not show any connections, does that mean the Media Devices of this Gateway are NOT being used?

Thanks Again,
Matt

Manish Gogna · ‎09-15-2015

Hi Matt,

If the output of "show sccp conn" shows zero connections then the transcoder / mtp from this gateway is not being invoked. You need to check the MRGL assigned to the devices involved in the call flow to see which resources are assigned in the top MRG.

You may check "show version" to see the uptime of the router.

Manish

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Matthew Martin · ‎09-16-2015

Hey Manish, thanks for the reply.

After I got T.38 configured on these 2821s with the help of TAC (*and g7llulaw fax passthrough as fall-back) I created a special MRG and MRGL for each of these 2821s. Inside each MRG for the 2821s I have the Hardware XCODE and CFB from that specific 2821. Then inside the MRGL for each of these 2821s I have the MRG I just mentioned as the top priority MRG (*one with ONLY the 2821's HW Resources), then I have 3 other MRGs listed under that one. One containing each of the CallManager's Media Resources and one containing the Hardware resources of the CUBE the call would originate from before it would hit the 2821.

The MAIN MRG for each 2821 looks like this, respective to each 2821's resources

2821-FAX01-MRG
- CFB_Rtr01-2821
- XCODE_Rtr01-2821

2821-FAX02-MRG
- CFB_Rtr02-2821
- XCODE_Rtr02-2821

Then, each 2821 has it's own MRGL. The MRG above for each 2821 is the first MRG listed in each 2821 MRGL... Like this below:

FAX01-2821-MRGL
1. 2821-FAX01-MRG
2. HQ-CUCM01-MRG
3. HQ-CUCM02-MRG
4. HW-HQ-MRG -->HW Resources of CUBE...

So given that MRGL configuration, it would seem to me that the 2821's resources would be used 1st (*if a Transcoder or CFB resource is needed for the call). Does that sound correct?

As for the show version output... It looks like the last time the gateway was reloaded was back on Sept 16th, which is a good bit before I posted this discussion... So I guess that's not the reason for this showing Registered now. However, there was some services restarted in CUCM the last few weeks so maybe that is the reason why...

Thanks again for the replies, much appreciated!

Thanks Again,
Matt

Manish Gogna · ‎09-16-2015

Hi Matt,

That is correct. If you have assigned a MRGL that has the CFB/Xcoder in the top MRG from this router then they will be used first. The reason for not seeing an output for "show sccp conn" could be because the call may not have invoked a transcoder at all.

And yes the restart of services on cucm or the ios upgrade of the gateway could have helped in the transcoder getting registered. Only if we had the screenshots , logs for the time when the issue was present and also we know which services were restarted on cucm we could have come to a specific answer.

Here is a good link for Media resources FAQ

http://docwiki.cisco.com/wiki/CUCM_Media_Resources_FAQ

Manish

Mohammed al Baqari · ‎09-16-2015

Hi Matt,

I am not aware about any command to track IOS changes. I usually track this apart from SolarWinds NCM server.

Regarding media resources, your CUCM isn't invoking any hardware resource from the router (CFB, XCODER, MTP). Do you think it should invoke a media resource for any reason like codec change, DTMF relay, etc?

If your call is working while CUCM didn't invoke media resource then probably you don't need it.

Matthew Martin · ‎09-16-2015

Hey Mohammed, thanks for the reply.

Ok, that's no problem. I was just curious about that...

These 2821 Gateways are used for faxing and I have worked with TAC a few months ago getting T.38 configured, with g711ulaw as the fall-back fax-passthrough method...

So I'm not sure if an actual Codec gets used to negotiate T.38..?

Thanks Again,
Matt

Mohammed al Baqari · ‎08-29-2015

Hi,

Please share your media resource config on both IOS and CUCM along with show sccp output

FrankLinn · ‎04-16-2025

I've been troubleshooting a similar issue where certain media paths seem to fail between the router and CallManager—especially when transcoding is involved. While testing, I stumbled on some interesting celebrity updates that were surprisingly engaging.

Anyway, has anyone noticed if setting up dedicated MTPs helps in stabilizing these sessions?