MOH Over PRI 2

[AlquestTech]

I have a problem with the quality of my MOH.

My music on hold sounds like it is playing underwater when heard over our PRI lines.

The music is from an external source but it sounds fine as BGM but it is really crappy over the PRI. I have tried adjusting the levels of the input but it has no effect. The music doesn't overdriven, just garbled.

Any suggestions?

 

[biv343]

This is a real long shot here, but make sure the clocking is correct (set to primary if the only PRI in the system).

I have never heard of this issue before. It's common over VOIP trunks, especially with G.729 with silence suppression enabled, but not on PRI.

 

[3Sixty]

Not to sure if this could be effecting it normally just does not work. What type of lead are you using to connect from the BCM to the external music source.It should me a 3.5 mm stereo to mono jack plug. I hope that it is the same standard as in the UK. The mono plug being the BCM MSC card.

Have you tried uploading some music in to the BCM amp and see if you have the same problem.

Marshall

http://www.marshallshouse.co.uk

 

[AlquestTech]

Hmmmm Biv, Now that you mention it... The clocking is right, however the PRI comes into A router First and then is passed to the PRI that goes to the BCM, even though both PRI's in on the same router, the router actually logs the call twice, once in and once out, so I am sure there is some VoIP manipulation there.
So you are saying it was due to the silence suppression using G.729?
Were you ever able to get rid of the problem?
I know the BCM is using G.729 and we might have silence suppression on the Cisco Router, I'll take a look, thanks!

yes mrmarshall the audio plug measurements are the same standards here, the problem does not appear to be with any of the cabling as the Background Music sound wonderful!

 

[biv343]

Silence suppression (or voice activity detection/VAD, depending on which Nortel camp you come from) can cause choppiness in MOH. Personally I never enable silence suppression/VAD, as it tends to cause more user complaints due to the system playing the "white noise" when there is silence in the background.

That's just my opinion though.

That being said, I'm sure silence suppression has it's place in a low bandwidth situation, as there is some bandwidth savings.

 

[AlquestTech]

Yes on the Cisco Router the setting is for VAD, however I do not have it enabled as I have experienced the same issues with the "white-noise" - of course the flip side of the coin is I have received complaints that the conversation sounds choppy and the customer thinks they are missing part of the conversation...

Anyway... Since I do not have VAD enabled for this Dial peer, do you think I should switch Codecs? I mean, have you experienced this problem yourself and is that what you did to clear it up?

 

[biv343]

I don't have any experience with PRI coming out of a router, short of "seeing it done" once in a lab.

I have had this problem on IP trunks with G.729, with or without VAD. I'm sure it has something to do with the sampling rate/payload size, but appears to be worse when the MOH volume level is lower. I haven't had those issues with G711.

Since I have no idea what your connectivity between routers is, its hard to say whether 711 will change things or not, or if you have enough bandwidth to support 711. Regardless, it may be worth a shot to see what happens.

 

[AlquestTech]

Thank you. You have been very helpful.

 

[NARSBARS]

With a direct input you are doing some internal translation to get to VoIP.
Mrmarshall suggested you upload some music and I agree.
Upload a wav file at mono 8khz and try it then.
Good luck.

NARSBARS

 

[AlquestTech]

Again, the music sounds fine when played as BackGround Music. This should eliminate the indication of any problem with the music source and its connections, especially since it is localized to just MOH and not BGM.

 

[hawks]

How does a Conference call sound over the PRI? Because I think when a call is put on hold it uses the conference circuitry for the MOH.

 

[AlquestTech]

Excellent point hawks, I tried a conference call and it sounds pretty good, actually all the voice sounds good, I am thinking the only difference is that music is a continuous sound source and voice is not.
The music sounds as if it is underwater...

 

[3Sixty]

Have you tried uploading the music on to the bcm amp and see if it sounds any better?

Marshall

http://www.fenixsolutions.co.uk/help

 

[AlquestTech]

Uploading it is not really an option as it is a licensed music source (Muzak) that is shipped to all of our phone systems and paging systems in the terminals.

I have checked the Cisco router and we are using G.711 Mu-law companding and no VAD....


Foldover maybe?

 

[3Sixty]

I am only thinking to rule out some problems. If it is the link you suspect then it will eliminate the CD player and the BCM.If it is still the same on the BCM the chances are it is the link as stated above

Marshall

http://www.fenixsolutions.co.uk/help

 

[AlquestTech]

I understand and even though logic dictates it is not the music source, it is never a bad idea to actually rule out possibilities through experimentation. I'll gwet my hands on some music and give her a whirl.

 

[NARSBARS]

Ruling out works in more than just medicine.
Don't forget to upload mono low bandwidth wav.

NARSBARS

 

[AlquestTech]

Yes it still sounds every bit as crappy when played as MOH...
=)

On a side note:
What a waste that whole BCMAmp is.. Do you know how hard it is to get a good quality wave file of music of any length in under 5Mb. As far as I'm concerned, until they support MP3 or other better types of compression, the whole thing is useless other than for messaging on hold.

 

[NARSBARS]

AlquestTech,

I am using royalty free music from this site.

http://www.incompetech.com/m/c/royalty-free/orchestra.html

I emailed the owner and he gave me permission to use his music. I translated to mono wav at both high and low bandwidth. The main reason for the low bandwidth is to minimize upload time and storage space.

The frustration comes in from how slow the site is, but he is willing to mail a cd for a fee.
The music sounds fine as background, on hold, and works to IP sets using G711. I don't think your original music sourc could be the problem but maybe this will come in handy at some point.



NARSBARS

 

[AlquestTech]

Yes, being as we are a public entity here and I am always asked to provide music for various events and what not, I am always on the lookout for royalty free and cheaply licensed music.

Thanks for the tip!