Voip help

[4ycr]

I need some help with this as I want to make sure I have this correct.

I have a client moving to new premises and they are going to get a dedicated 80/20 LLU line but was advised to also get ADSL2+ 21CN for their VoiP as it uses SIP and that can't work on their LLU line. this is according to their VoiP provider but someone else said different.

Anyway the ADSL line is 6Mb down and 1Mb up and according to information I have seen online this would only support 8 maybe 9 calls at the same time.

I am not a broadband or VoiP supplier but they wanted my opinion on it.

They currently have about 12 VoiP phones but this will be increasing to about 20 with 10 being for a call centre

 

[4ycr]

forgot to say their voip solution is hosted if that makes a difference.

 

[Markverhyden]

Rule of thumb from what I have seen is 128kb per phone but actual pipe size varies by codec.

http://www.cisco.com/c/en/us/support/docs/voice/voice-quality/7934-bwidth-consume.html

But that does not necessarily mean that the quality will be great. What I have seen is situations where one would expect the VoIP system to work. But in reality there are things going on in the background that cause problems.

Many sites will have two accounts, one for Internet and one for VoIP so they do not have to engage in any QoS exercises. The VoIP circuit is specifically designed for that (what ever that means). Personally I think a lot of ISP's are more interested in selling you their VoIP than figuring out why some customer has a 3rd party VoIP service issue.