Which VoIP Adapter?

Gavin1

Hi,
I am considering going down this road with my NTL 3meg subscription. I am looking at Blueface and they seem to be well thought of and customer friendly.

The problem is that if I ditch Eircom and the performance/quaility is not comparible I will be getting the "I told you so" lecture. So with this in mind could you advise me on a good quaility adapter.

Regards and thanks in advance.

medO

Gavin1 wrote:

Hi,
I am considering going down this road with my NTL 3meg subscription. I am looking at Blueface and they seem to be well thought of and customer friendly.

The problem is that if I ditch Eircom and the performance/quaility is not comparible I will be getting the "I told you so" lecture. So with this in mind could you advise me on a good quaility

Generally the weakest link in VoIP is the link between your ISP and your VoIP provider. If you set-up a home network and put VoIP kit in your bedroom and downstairs the call quality between the two will be excellent (ie as good as/better than ISDN and far better than POTS).

The safest route is to try a VoIP ISP using their downloadable (usually free) software client. If it works out OK, chances are it will be even better using a VoIP phone or adapter. No point in ditching your eircom PSTN or ISDN service until you are happy over a period of several weeks at least.

medO

Cabaal

medO wrote:

The safest route is to try a VoIP ISP using their downloadable (usually free) software client. If it works out OK, chances are it will be even better using a VoIP phone or adapter. No point in ditching your eircom PSTN or ISDN service until you are happy over a period of several weeks at least.
medO

I'd certainly have to agree with testing via the software, its important to remember that running such things as bittorrent will affect quality unless you cap them at certain upload/download speeds.

For example I have found that I must leave about 12k upload free in order to be able to make a decent quality voice call so if I have anything uploading its capped to 20k/sec up max.

I don't know if I agree with testing for several weeks, I guess test it for as long as you deeam necessary and then make then jump to a VoIP phone or ATA.

WillieFlynn

Testing a VoIP provider using softphone as compared to trying with a hardware adaptor. May give quite a different impression depending on your computer and the software it is running. For example internet browsers tend to hog a lot of memory.

I would suggest that you keep your normal phone line for awhile, untill you are sure you are happy with the VoIP. Remember that unless you have QoS giving priority to the VoIP traffice, any large data usage could cause problems. The sipura 2100 (which blueface sells) has QoS built in. Some of the newer routers / switches also provide QoS control. If you make many intenational calls the price difference will very quickly pay for the extra hardware, while giving you time to show how well it works :-)

Also remember that if you have a powercut your VoIP setup will not work unless you have a UPS installed. However the sipura 3000 has automatic fail over to a normal phone line in the event of power cut or loss of internet connictivity.

Or if you just need the simplest VoIP adaptor for one voip phone line the sipura 1001 or for two independant voip phone lines the sipura 2000 will do.

As you may have gussed form the examples, I am more famillar with the sipura range.

I personaly have found that using a sipura 3000 with blueface. Gives the same quality as a normal phone both when connected using netsource or when I used it with a cable modem in Texas when on holidays. Unless I swamped my internet connection with a big download.

Willie.

elmer

anyone got any opinions on the grandstream kit

air

I installed a Netgear RT31P2 from Blueface today and its working well.
I'd recommend it to anyone looking for a 2 port gateway with QOS.
I think I'll need a 4P gateway with QOS soon though.
Anyone want to suggest one?

causal

Thanks for the feedback on the RT31P2 - do you wanna post your setup in the setup thread

Why do you need 4 ports?
Would it be handier to simply use a multi-adapter or a DECT basestation with additional handsets?

causal

bhickey

elmer wrote:

anyone got any opinions on the grandstream kit

I think that all of the more common adapters (Sipura, Grandstream, Linksys etc.) will work fine as long as your broadband connection is reasonably good. More important is that you pick one with the right features based on your requirements (e.g. how many handsets/phone lines/LAN/WAN ports the adapter can handle). A useful feature too that some adapters have is that the adapter can terminate an incoming analogue call to an outgoing VoIP call. This can be handy for example here a business might want to retro-fit a VoIP facility to an existing PBX.

air

bhickey wrote:

the adapter can terminate an incoming analogue call to an outgoing VoIP call. This can be handy for example here a business might want to retro-fit a VoIP facility to an existing PBX.

You've lost me here, can you explain this capability a bit further?

I want a 4 port adapter because I'm using it in an office that has two phone lines and a fax line as well as a pbx which currently has 16 users.
I want to transfer the two voice lines to VOIP and have an additional two lines which I will prioritise for outgoing calls on the pbx so as to keep the other lines free for incoming lines from clients.
This will save the rental of two analogue lines (circa 500 pa) and I can just have one analogue line for the fax & have the DSL on that.

The only problem I see in my master plan is that my eircom business broadband connection has a ridiculous 128/2mb ratio. I doubt 128 would be enough upstream bandwidth for 4 simultaneous VOIP calls.

causal

128kbps is fine for 4 VoIP calls - 128/4 = 32kbps each
- but you should choose an optimal (bandwidth Vs. quality) codec e.g. G726 (16, 24, 32, 40 kbps)
Note that your linksys RT31P2 supports "Voice Codecs G.711 a-law, G.711μ-law, G.726, G.729 A, G.723.1"
- then look here for the bandwidth requirements for differenct codecs

Your theoretical max calls is to use G723.1 for 24 simultantous calls @ 5.3kbps each - but minimising voice quality*.
Your theoretical min calls is to use G711 for 2 simultantous calls @ 64kbps each - but maximising voice quality*.

QoS certainly required - especially if that 128kbps is also used for email / web access etc.
For reference skype say that it will work with a minimum of 24kbps (max 128kbps).

I'm slightly confused over where the 4 VoIP calls come from with 2 VoIP lines
You're keeping 1 eircom line dedicated for dsl & fax; 2 VoIP lines - does the PBX have a max of 4 calls?

hth,
causal

* - this is voice quality - what happens those voice packets on the journey is at the mercy of your bb connection and the internet.

puma5k

elmer wrote:

anyone got any opinions on the Grandstream kit

I have about two Grandstream 102's setup on a 3com router with an 2mbit breeze wireless Connection from IBB
The IP Phones are easy to setup just login and change about 4 setting and your away, I would recommend upgrading the firmware as they are shipped with on old one.
At the start is was working good but then go a few crackly calls on it when i was downloading stuff but I called blueface and IBB and they tweaked my connection and it's working great! I can put as much as traffic on the Broadband connection and get excellent quality call at the same time,

VoIP can be very reliable once your VoIP traffic can be kept at a priority within your own network and on the WAN side to the VoIP provider.

bhickey

air wrote:

You've lost me here, can you explain this capability a bit further?

On your PBX (assuming you have analogue lines connected to it) you could dedicate 2 output lines to VoIP by attaching either of :

Grandstream 488 http://www.grandstream.com/y-ht488.htm
Sipura 3000 http://www.sipura.com/products/spa3000.htm

to the output lines (or analogue extensions). Depending on how much configuring you're able to do on your PBX, people can dial a particular extension and get a "dialtone" from the VoIP box or else you can route certain calls (e.g. International) to the VoIP boxen. The VoIP box acts as gateway device. Most ATA's don't have this option but the above 2 do.

Given that you want a total of 4 voice lines on a 128Kb upload though I think you're main focus will need to be on QOS.

air

bhickey wrote:

On your PBX (assuming you have analogue lines connected to it) you could dedicate 2 output lines to VoIP by attaching either of :

Grandstream 488 http://www.grandstream.com/y-ht488.htm
Sipura 3000 http://www.sipura.com/products/spa3000.htm

to the output lines (or analogue extensions). Depending on how much configuring you're able to do on your PBX, people can dial a particular extension and get a "dialtone" from the VoIP box or else you can route certain calls (e.g. International) to the VoIP boxen. The VoIP box acts as gateway device. Most ATA's don't have this option but the above 2 do.

Given that you want a total of 4 voice lines on a 128Kb upload though I think you're main focus will need to be on QOS.

This is exactly what I'm doing, I have it working already.
I dont really understand why only those 2 analogue adapters would work, i would imagine that you could combine any analogue adapter with any pbx with an analogue card.

causal wrote:

I'm slightly confused over where the 4 VoIP calls come from with 2 VoIP lines
You're keeping 1 eircom line dedicated for dsl & fax; 2 VoIP lines - does the PBX have a max of 4 calls?

Yep, it has a 4 port analogue card so I want to get 4 VOIP accounts, 2 to support incoming calls on the 2 existing landline numbers and 2 for outgoing calls only, just to keep the other two lines free for incoming calls.