MOH badly distorted

[MitelInMyBlood]

I'm in the middle of a CUCM (Rls 8) rollout & attempting to use the USB Audio dongle for a commercial (subscription) music source (like MUZAK). Customer is moving from a Mitel TDM system and has call centers w/clients on hold, sometimes for several minutes. Complaint is the MOH on the new phone system is distorted (and I agree, it is noticibly bad). We've tried adjusting levels, impedance matching, etc all no improvement. Any suggestions?

Original MUG/NAMU Charter Member

 

[biglebowski]

What codec is the source? by default it only supports G711

Biglebowskis Razor - with all things being equal if you still can't find the answer have a shave and go down the pub.

 

[MitelInMyBlood]

G711. I suspect there's an issue w/QOS. Vendor/VAR in looking at it now. Seems like programming in CUCM is like building sand castles w/tweezers and a magnifying glass. In 25 yrs supporting phone systems, even 5ESS central office, I can honestly say I've never seen a more granular programming interface.

Original MUG/NAMU Charter Member

 

[MitelInMyBlood]

After looking at it, the Vendor/Var says MOH "is what it is" - unfortunately it sounds like hell. They're recommending we consider using .way files. That's not what CISCO sales told us. We were told we could continue using our live MOH feed. It's not being overdriven and not an impedance mismatch. Audibly it sounds like a QOS problem but right now we're in the early stanges of rollout (only 25 phones deployed) on a gig VLAN and there's virtually no competing traffic.

Original MUG/NAMU Charter Member

 

[whykap]

That's not a QoS issue if you are on the LAN. If it is then your network has serious issues (doubtful).
If your vendor cannot fix it and they sold you this solution then they need to step up.
External MoH does work off a live feed so don't let them tell you that. Have them open a TAC case if they can't fix it themselves.
Is the MoH feed going into the ccm server or a router?
i highly suggest you use a router to do that.

 

[kcbell]

mitelinmyblood:
MOH has been haunting me for months. My issue is MOH volume is too loud. It is a 5 second job to adjust the volume for any PBX. With UCM, I need to re-import the wav file and adjust the input gain to a different level before I import the file. After I imported the file, the volume is lower but the music has random clicking sound. I have a TAC with Cisco for months now and I am heading to the USB solution.
They asked me to send them log files and trace files etc. It just took up too much of my time to deal with this "little" thing. I gave up!
I can feel your pain because I was a PBX admin for years. VAR does not own your problem - Cisco does! This is a very poor design to import a WAV then the system does something with the file. At one time, TAC imported my music file to their Lab and told me that they cannot duplicate my problem in the Lab. I told them to send me the imported file then show me how to apply it back to my system. After couple days she came back and told me she cannot send it to me because they build the system security so tight that there is no simple way to import a file back to the system!!!
Either solution should work with no issues. The imported WAV file method was working fine. We just did not notice the volume was too high until recently. I did another import last night in the middle of the night hope that the system was quiet and the computer can dedicate more time to the import task. The result is the same. There was clicking sounds.
I have another TAC with Cisco that has lasted six month now. It has to do with Unity. Some users, not all users, cannot access their voice mail via the phone. Unity broadcast the message, “you voice mail is not available now”.
Being a sys admin for Call Manager and Unity for two+ years, certain VOIP features are still in development mode! Take care!

 

[MitelInMyBlood]

We were able to solve this distortion problem. The problem was the USB dongle. We RMA'd it and the replacement is fine. Yes, levels are hot, to say the least. We've padded-down -20 and they're still hot (compared to the Mitel system) but much improved. We also had hum/distortion because the Mitel was accustomed to seeing the MOH audio fed to it over an E&M trunk and the input to the MOH dongle is high impedance. We solved that problem with a Bogen WMT-1 impedance matching transformer.

Original MUG/NAMU Charter Member