IP telephony

[DaveB]

Thanks for these thoughts. Latest is BT are replacing the Quantum with the Avaya and funding the installation and rental of a third ADSL to be dedicated to VOIP, pending FTTC.

I'm still refusing to pay for anything until it all works.

Its tortuous though.

Welcome to dealing with BT

They sold a previous client co a PABX system based on specific technical requirements and then delivered something not even close and pointed to a contract clause that said "...or equivalent..." in relation to the hardware to be supplied.

The original spec called for a full size server with redundant NIC's, power supplies etc, and they delivered a pizza box PC with zero redundancy for the same price. It took 6 months to sort out.

[Jessica@WhiteFieldTax]

Thanks for these thoughts. Latest is BT are replacing the Quantum with the Avaya and funding the installation and rental of a third ADSL to be dedicated to VOIP, pending FTTC.

I'm still refusing to pay for anything until it all works.

Its tortuous though.

[Manc Marvel]

IP Telephony

Can I request some tech advice from anyone in the know, quid pro quo for the help we (try and ) give on the accounting thread.

Issues re bandwith for IP connectivity.

We've been lead a merry dance by BT over the last 8 months with a "integrated phone and connectivity system".

There are seven of us here, working "lifestyle" hours. Only myself and my PA in the main office, everyone else works from home.

We had a phone system specified by BT to provide two ISDN lines into the office, two business ADSL lines, and three homeworkers via VOIP.

At the time I questioned them at some length over bandwith as we are in the middle of nowhere, with corresponding broadband speeds.

We get 0.5Mbps up, 3Mbps down, line quality A, on each of two ADSL lines. Those lines then service, via load balancing router ( professionally configured), the VOIP x 3 homeworkers, exchange, web browsing and up to 5, but normally less, concurrent RDP sessions.

I was told, initially, the bandwith requirement was around 70k for a IP call, 50k for a RDP session. That seemed to give us ample capacity.

Incidentally, our local exchange gets fibre next month, and we have a date for fibre to cabinet The cabinet is a mile away over old copper No satisfactory WiMax in area.

The VOIP aspects of the system have never worked well - call quality very poor and call drop outs -and trying to get sense out of BT has been frustrating over 6 months. Engineers kept saying there "not enough bandwidth", we responded "thats not what you told us at the outset and you sold us lines plus phones as a integrated solution". Repeat to fade.

Anyway, after I took to venting my fury about BT on twitter they've perked their ears up, and we had area sales director out today, offering to upgrade the system.

But I couldn't get anything definitive about bandwith requirements.

I appreciate configuration and compression makes a difference, but assuming a competent set up, what is the bandwith requirement for VOIP?

If we assume up to 5 RDP connections and up to 3 voip calls, worst case, what should our requirements be?

We've got good local IT support, and they have tweaked as much as they can on the RDP connections, router balancing, etc.

I've had one supplier telling me they could run a call centre with 50 VOIP users off our line, claiming 5k per call, whereas BT were muttering something about 400k per call this morning. A big difference.

Any thoughts from an independent source would be welcome.

Incidentally we have a BT Quantum system at the moment (£2,000), they are offering us a free upgrade to a Avaya IP office (£3,500)

All the data BT have provided on bandwidth required is correct, if not overstated. Your problem is the ADSL, the performance figures are 'typical' performance but at any point in time can drop to zero. The fibre to one mile may well improve your service as the signal will be regenerated at the cabinet whereas now its only from the exchange - dont expect 20meg though! however reliable 1/8 should be possible - get BT to comment on this aspect. You might also ask the contention ratios on your service and how many other customers there actually are - the more simultaneous users the lower the instantaneous throughput you get as you all share this same bandwidth. Another tip is when the VOIP is in use don't use the internet for anything else. I assume virgin media and co are not available.
Assuming you are IOW I checked your postcode on BT Broadband (ps lovely part of the world)
There results are even worse than quoted avbove 1meg down and no guarantee up - BT should not have recommended VOIP with this level of ADSL. Your only hope is the FTTC upgrade post 31 march

[Fishface]

Dd-wrt + milkfish for voip.

Adsl is always a problem get a cable laid to your office.

[Normie]

One thing you might want to consider is RDP acceleration/compression. Not used it myself but heard good things of Ericom Blaze:

Ericom Blaze RDP compression and acceleration software

So this replaces the RDP client and server software I think - i.e. you install the Blaze software on your server and use the Balze client on your remote PCs. May free up some bandwidth for your voice calls.

Regarding native RDP performance, the bandwidth use very much depends on the version of RDP being used by the client (i.e. what Windows version) and the version of RDP on the server (what server are you using). Then a lot of things like ClearType and Font Smoothing can impact performance, along with the chosen colour depth, etc. A bit old now, but some useful info in the following document:

http://download.microsoft.com/downlo...hitePaper.docx

HTH

[Jessica@WhiteFieldTax]

There'll be geeks out there researching this very minute Jessica.

In the meantime this might help.

VoIP bandwidth fundamentals

Thx I'll check the link out

[Jessica@WhiteFieldTax]

Thanks ThomserveBAS - those bandwith thoughts from vonnage are helpful to give me a context.

We use pingtest regularly - and it nearly always tests out as A. Sometimes drops down in wet weather, as I think joints get damp - in years past we would loose all broadband in heavy rain. Crap, huh?

RDP connections should be low load - spreadsheets, text and similar rather than multimedia stuff - PDFs are always a bottle neck though, with slow rendering.

IT support have tweaked loads every which way they can, but the phone doesn't seem to improve. Thankfully RDP quality hasn't suffered and there are no user complaints.

[ThomserveBAS]

I use Vonage at home, and looking in my control panel, their bandwidth can be scaled from 30kbps (which they term "normal" quality) up to 90kbps ("highest") - I always use the highest setting and there is no discernible difference between that and a landline/mobile call.

One thing that can affect VOIP more than bandwidth is latency (if you go to Pingtest.net - The Global Broadband Quality Test it will tell you how your current latency could affect certain real time services).

The quoted bandwidth for RDP sounds very low - I'd imagine the user experience would be pretty naff with such little bandwidth although the link below suggest that RDP is "happy" to work under such constraints depending upon the type of application being used (i.e. a large multimedia rich presentation will consume far more bandwidth than a spreadsheet).

[cojak]

There'll be geeks out there researching this very minute Jessica.

In the meantime this might help.

http://www.computerweekly.com/featur...h-fundamentals

[Jessica@WhiteFieldTax]

Can I request some tech advice from anyone in the know, quid pro quo for the help we (try and ) give on the accounting thread.

Issues re bandwith for IP connectivity.

We've been lead a merry dance by BT over the last 8 months with a "integrated phone and connectivity system".

There are seven of us here, working "lifestyle" hours. Only myself and my PA in the main office, everyone else works from home.

We had a phone system specified by BT to provide two ISDN lines into the office, two business ADSL lines, and three homeworkers via VOIP.

At the time I questioned them at some length over bandwith as we are in the middle of nowhere, with corresponding broadband speeds.

We get 0.5Mbps up, 3Mbps down, line quality A, on each of two ADSL lines. Those lines then service, via load balancing router ( professionally configured), the VOIP x 3 homeworkers, exchange, web browsing and up to 5, but normally less, concurrent RDP sessions.

I was told, initially, the bandwith requirement was around 70k for a IP call, 50k for a RDP session. That seemed to give us ample capacity.

Incidentally, our local exchange gets fibre next month, and we have a date for fibre to cabinet The cabinet is a mile away over old copper No satisfactory WiMax in area.

The VOIP aspects of the system have never worked well - call quality very poor and call drop outs -and trying to get sense out of BT has been frustrating over 6 months. Engineers kept saying there "not enough bandwidth", we responded "thats not what you told us at the outset and you sold us lines plus phones as a integrated solution". Repeat to fade.

Anyway, after I took to venting my fury about BT on twitter they've perked their ears up, and we had area sales director out today, offering to upgrade the system.

But I couldn't get anything definitive about bandwith requirements.

I appreciate configuration and compression makes a difference, but assuming a competent set up, what is the bandwith requirement for VOIP?

If we assume up to 5 RDP connections and up to 3 voip calls, worst case, what should our requirements be?

We've got good local IT support, and they have tweaked as much as they can on the RDP connections, router balancing, etc.

I've had one supplier telling me they could run a call centre with 50 VOIP users off our line, claiming 5k per call, whereas BT were muttering something about 400k per call this morning. A big difference.

Any thoughts from an independent source would be welcome.

Incidentally we have a BT Quantum system at the moment (£2,000), they are offering us a free upgrade to a Avaya IP office (£3,500)