VoIP Questions - Gateway/ Codecs/ Phones

[shuey227]

I looked for the following information but could only find bits and pieces scattered all around.

I am looking to setup a VoIP system for a small business, with 3 or 4 phones and 3 or 4 lines. I setup 3cx on a Win2k3 server, using Grandstream 2000 phones, and Broadvoice as the carrier. It all works however the quality is quite poor for business purposes.

I am using the GSM codec on the phone, but looking on Broadvoice's website they only support G711u, and in the future G726-32 at 32kbps and G729a at 8kbps. My calls are taking between 60 - 80 Kbps, so from what I've read that isn't GSM, which is supposed to be around 20 Kbps.

Here are my question:

a) What is the best codec to use for 3-4 lines on a DSL line? Low bandwidth and decent quality...

b) What VoIP carrier uses those codecs? Which ones are the best (USA New York)

c) Will the Grandstream 2000 support those codecs? If not, which phones do I need to get?

Thanks for your help!
Dale

 

[SY]

check this thread http://www.3cx.com/forums/viewtopic.php?t=1902&start=0&postdays=0&postorder=asc&highlight=
There are answers for your questions regarding bandwidth.

 

[shuey227]

i read that forum, but only answers part of the question.

 

[archie]

I would suggest you to try direct connection from Grandstream (or softphone) to Broadvoice. It may happen that voice quality is not a problem of PBX, but Broadvoice itself, or your DSL link. Also, in Grandstream settings you can change priorities of codecs to find the best one.

 

[shuey227]

apparently broadvoice only G711u, which isn't an option on the phone. the options in the phone are:

GSM
G.723.1
G.729A/B
PCMU
PCMA
G.726-32
G.722 (WIDEBAND)
iLBC

 

[SY]

apparently broadvoice only G711u, which isn't an option on the phone. the options in the phone are:

GSM
G.723.1
G.729A/B
PCMU
PCMA
G.726-32
G.722 (WIDEBAND)
iLBC

it is G711

 

[archie]

G.711u is exactly PCMU
Anyway, even if Broadvoice supports only PCMU - it worth to try direct connection from Grandstream. If quality of direct call is better that thru PBX - let us know, and we could try to tweak your settings

 

[Costas3CX]

As SY and Archie already said before,
G711u=PCMU and
G711a=PCMA

they are the same thing. Just a different name for them...

 

[shuey227]

thanks for your help.

next question - i am looking for 3-4 lines (let's go with 4 for this case) and looking for a voip provider (New York) but want to use the same outbound caller ID for all calls. when i contacted broadvoice they had said i would need 4 lines. is there a provider that can handle 4 calls on one line, or perhaps use the same caller ID?

thanks for all your help

 

[AndrewRTS]

Hey shuey...
You might want to try Junction Networks:
http://www.junctionnetworks.com

I've been very impressed with them and the call quality has been spectacular. I have only set them up so far as outgoing, as I'm waiting on my regional DID numbers to port, but on outgoing it's perfect with 3CX.

 

[shuey227]

thanks for the info. should i be looking at the sip hosting?

shuey

 

[AndrewRTS]

I just signed up for the PSTN gateway. That was the closest to a traditional "phone line". I just received the authorization form to get my numbers ported. Yeah!

Their support has been spectacular, and I had the outgoing calls working in about 3 minutes on 3CX.

 

[shuey227]

echo cancellation

i'm trying a variety of voip providers and every once in a while i seem to get choppy or an echo. how can i solve the choppy echo?

thanks!

 

[SY]

Re: echo cancellation

i'm trying a variety of voip providers and every once in a while i seem to get choppy or an echo. how can i solve the choppy echo?

thanks!

If you hear yourself with delay then it is not related to 3CX PBX.

Regards