sundance-communications.com/forum Forums VOIP Phones & IP PBX VoIP & Cloud Phones, Hosted PBX, General IP Phones Sprint FlexiCom500 Voice Quality Problems

It's been over a year of dealing with voice and voice mail quality problems in our branch office. We have a ISDN in our corporate office of 35 employees and rarely have any problems. We bought the identical system for both offices but the branch office taps into the voicemail of the corporate office and their voice mail quality is horrible much of the time. It makes sence to me that it's caused by the 768k DSL. What doesn't make sence to me is that the branch office is frequently unable to hear incoming callers while the incoming caller hears them ask "Hello is anybody there?" Note that the the branch office has only 6 Pots lines and is an office of 15 employees.

The company that sold us the phone system has no solutions to offer anymore saying that the problem lies with the other vendors even though they recommended the equipment that is now in place. I can provide addl info if asked...any ideas? I so appreciate your expertise!

Coraltech should chime in your problem. I think you have answered your own problem if you are using networking with 768k. You are probably looking at a QOS issue.

That is not enough bandwidth IMHO. Usually DSL is 768 down and 128k up. That could cause one way audio big time. You also need to check ports. If this IS dsl I highly doubt you have and any way to have QOS over the public internet. VOIP can ONLY work well like this if you have either dedicated bandwith or some sort of frame relay both solutions with QOS on the routers. This is without a doubt a NETWORKING issue. ARe they doing your IT as well or is your IT dept in charge of the infrastructure?

Usually DSL, cable modems are used for small home offices, not a remote office with that many people.

Thanks for your quick reply...
According to the DSL provider (and it really is DSL) they are as close to syncrinis(?)as possible and we "should" be getting a dedicated 512 down and 512 up but it's not guaranteed($$). He also stated that they don't block any ports outside of virus's and they do put voice packets first. He also agreed that 15 phone lines at one time is too much (5 would probablly work).
I've been looking at replacing the DSL with a 5.0 kbps down & 1.0 kbps up cable connection instead of going to a T-1 due to budgetary restraints. Is that fast enough for the size of that office?

We use an outside IT firm that is responsible for the infrastructure but they been relying on the phone system firm to recommend the switches and firewalls who has been relying on the carrier to provide acceptable service (which they said was suitable from the get-go). Of course none of them claim responsiblity for this ongoing disaster.
Anyway, we are currently using 3Com Superstack 3 Switches(4226T 24Port Plus 2 10/100/1000 RJ45)If that means anything to you. and 50 user Watchgard(10meg)firewalls on both ends. I saw somebodys comment that 100 was preferable? Also, we have no frame relay on the routers.
Again, thanks in advance for your help!

Ok, here is the deal. Routers prioritize packets through a QOS header or some use DIFserve..same deal or you can simply prioritize port traffic. From your list I see no routers and a big red flag. You HAVE to have a router on each end to make this work correctly. Internally I seriously doubt you will have bandwidth issues because, hey 100mb switched is fast for voice. Not having dedicated service point to point or some sort of manage network service, I am pretty sure, makes QOS impossible over the public network unless I am missing something here. More bandwidth cannot hurt, ever, well unless you get huge latency of some sort.

Ok, let me get this straight, you have a remote office using FXO-IP converters and 15 telephones over a DSL going into the Coral, probably through a Sentinel correct?

Ok, some hard choices. How far is your remote branch? If not far think about point to point T1's or wireless or frame.

Think about getting a local phone system and voicemail and network the systems via IP to cut down on bandwidth needed for internal calls.

No matter what though you don't have enough bandwidth..make that MANAGED bandwidth. You have to understand the difference between home office and a real office with more people.

The trick to IP, and making it work, is having a network that can support it. I can tell you from experience 75%-80% of networks today cannot support VOIP well or at all. Too few people understand the importance of a managed network because data, unlike voice does not require priority and constant streaming to work properly. That being said, it can be fixed, but it depends on the monies you want to throw at it and how important it is to get calls at a decent sound quality.

Thanks Coral Tech,
I appoligize, I don't know the lingo (I'm just an accountant). When you say "router" are you referring to the DSL termination point (modem)? Would the Point to Point circuit have a router on each end then the router into the firewall? I do hear what your saying about a managed network and will persue that route with a new carrier.

You asked-The Branch office is 70 miles away.

In an attempt to clarify what I said in my original posting...
We have a Flexicom IPx 500 System in EACH office and EACH office uses FlexSet 120D digital phones(no IP phones).
The branch office taps into the corporate office (via the DSL)for voice mail, email & data but they have their own 8 pots lines so that if our phones go dead the branch office still has phones but no voice mail (we turned off the least cost routing a year ago for trouble shooting purposes)and if our terminal server goes down they have no email and data.

FYI-There is a great deal of construction in the area and the phone folks tell me that if the power goes out (after UPS dies) re-setting the phone system will clean up the problem and it does for a while but we doen't know if the power is going out. We also frequently have to reset our watchgard units when the branch office data frezes up.

anyway, I called Tanderan (formerly Sprint) and asked why the branch office can't hear the incoming caller on their pots lines and he thought that possibly the pots lines were not in spec. he said neg2 or neg3 DB should be ok and Sprint would be able to adjust the gain but neg4 or neg5 (though technically in spec)would cause voice quality problems. So I called the Pots carrier and they said the lines tested fine but I'm having a tech out tomorrow to check them out in person. They will not tell me what the specs are though. Sprint said that the lines may just magically fix themselves a few days after my complaint. I can only hope!

Is that more clear? Thanks for your patience!

Addl thought:
In your experience, does VOIP work well on analog lines with this phone system?
And if so, is it possible that the phone system is not setup properly?

Because I'm still here pestering you that means I haven't been fired for this...yet.

VoIP has nothing to do with your analog pots lines unless they are delivered by a carrier that brings lines in that way. From your description the only VoIP part is the connection back to the main office for intercom and voice mail functions. Every call on the local lines low volume? I'd recheck...

Thanks Rather Be Fishing,
You said- "Every call on the local lines low volume?"
Please explain, I don't know what you mean.
Jeanette

It's been a long awhile but I recall the phone provider saying that they have adjusted the volume (I guess) as much as they can.

When I told them that it may be incoming cell phone callers they told me that the phone system is so sensitive that if a cell phone is cutting out it would disconnect the call.