Voip

[Weylander]

Anyone using VOIP at their workplace? I need a little advice......

Our ISP doesn't guarantee Quality of service, we have 512mb connections between 4 small offices (20 users in each) and a 2mb connection into the cloud from the main office. Traffic between sites is pretty low at the moment so 512mb connections are more than enough. But if we were to install VOIP phones for use between offices, would this create a problem. I have heard that without QoS, Voip packets could be dropped during network busy periods resulting in bad quality telephone conversations. Any info is appreciated.

What we are after doing is, having a freephone number and a central exchange at the main office, then transferring the calls to the destination office over the existing IP network infrastructure and all office to office calls between staff go VOIP, we believe this will result in a 30-40% decrease in call costs, which is a lot of money.

 

[Chilly]

Assuming you mean 512KILOBIT per sec connctions (not 512mb as you wrote, which is an odd number) you may run into problems when you get more than a couple of people on the phone at the same time, which in a 20 man office won't happen ALL that much but will occasionally, and will be annoying when it does.

QoS is to do with your own network infrastructure, but what your ISP provides is probably a contended line, 1:20 or whatever, so you may find the line gets very crowded at times.

 

[Weylander]

WHOOPS!! yes i meant 512Kb!!! sorry.

Thanks for the info, contention is 1:20 afaik. So what would be the best course, I have a couple of choices, upgrade the lines with our current ISP to at least 1Mb or change over to a new ISP that guarantees QoS at a much much higher rental price. Hmmmmmm!!!

 

[Lester]

You have to bear in mind your upload speed more than your download. You will only get a max of 256kbps whether you have a 512 or 2Mb connection, which on a 20:1 contention service, could be as little as 12kbps net (not likely but worse case). Your voip traffic will run at around 44kbps (more if you use a soft phone) per call, so don't expect miracles.

You have a couple of options

price up a low contention service (uncontended on a normal connection would give you 5 voice call capacity per remote office)

Avoid the Internet. You can buy a DSL service that won't traverse the Internet - this will remove some of the "bursty" traffic issues.

Get a symmetrical SDSL service (you should for you main office anyway)

Several ISPs are now offering QOS over DSL. It's not true QOS, but they do offer a better voice experience than the normal service.


All options cost money, but if you know what your site to site calls cost per annum, you should be able to build a business case and decide a budget.

cheers

 

[Lester]

Where in Geordie land are you by the way?

 

[Lester]

Fuck me!

reading through this pissed, thinking what an intelligent reponse the last note was and it was me!