[Mac-telephony-list] VOiP Gateways / Bridges

[Martin Joseph via List]

On Jun 2, 2007, at 8:54 AM, Flavio Donadio via List wrote:

> Hello!
>
Hello.
>
> I am considering switching from my hardware PBX (which kind of sucks,
> to be honest) to an Asterisk/Afelio/OpenPBX/Whatever-based solution
> for a long time now.
Seems like a good idea.  I recommend waiting a bit longer. While you  
are waiting,  have you built yourself and asterisk or Afelio or  
whatever box to play with.  I recommend that also.
>
> I already asked some questions, got some answers, but I'm still not
> confident enough. The hardware I need is still a little expensive for
> my budget. I am afraid of cheap stuff, since I already got
> disappointed with my current setup. I want to get a "permanent"
> solution.
>
> We have an E1 with 30 voice channels, digital R2 signalling, supplied
> by Embratel, one of the biggest enterprise-oriented telcos in Brazil.
> Last time I checked, people suggested me a VoIP gateway which, from
> my understanding, is a box that connects to the central office
> through my E1 (which "runs" over a radio link) and communicates with
> a switch or PBX through an IP network, using SIP, IAX, H.323 or
> whatever...
Yes that sounds reasonable to me. Although I have no experience with E1.
>
> So, with this in mind, I think I need at least a VoIP gateway and a
> computer (Asterisk server). I would also need a way to connect my
> extensions to the server, and that could be made through a lot of
> different ways: FXO ports for analog phones; software IP phones on
> computers on the network; and hardware IP phones on the wired network
> (or Wi-Fi phones on a wireless network).
>
> Well... If that's correct, I am figuring a set-up like this:
>
> • Epygi Quadro E1/T1;
> • PowerMac G3 350MHz;
Why so little of a mac?  I am using a G3/400 imac with a  dead screen  
as my primary asterisk server,  but I only pass a call or two or  
four.  Thirty calls seems like a lot to pass through a G3/350,  
especially if there is the possibility of transcoding audio formats...
> • Linksys WIP300 Wi-Fi phones.
>
> I am considering the Wi-Fi IP phones because I already have a
> wireless network set-up and running well. Though, the 3Com AP seems
> to be a little crappier than I thought it would be and I am
> considering switching it for a better one.
I am using Zyxel with good results.  It has a lot to do with your AP  
density and positioning also.
>
> My questions:
>
> 1. Have anyone here used the Epygi Quadro E1/T1? Is it any good? Is
> there any good (or better) hardware at the same cost ($2,300.00 USD)
> or even cheaper? I am considering it because it is certified by
> Anatel (the equivaldent to FCC here in Brazil). Cost is a serious
> concern to me but, as I said, I am afraid of cheaper and crappy
> stuff. This is the cheapest gateway I've found that seems to be good
> enough.
No Info, but you are very smart to avoid the cheap stuff.  I started  
out using Grandstream for my FXO, then threw that out and bought  
another 3 times expensive box (still cheap), which died, and finally  
sprang for an Audiocodes 2FXO/2FXS box (about 400US$) well worth  
every penny, wish I had bought it to begin with.
>
> 2. I considered the G3 because I have no use for it as of now, and
> see no chance in putting it to any use. This box is getting old fast,
> but I think it's still a good machine and I can mount it on my rack
> with the appropriate hardware. Will it handle 10 to 15 extensions (I
> have 7 extensions now and don't expect having more than 15 in the
> next 18 months or so)? From what I have seen on this list, I guess
> this G3 will do the job.
Depends a lot on whether it's transcoding audio,  if it is, you need  
more mac.

Also,  for a production environment like you are describing, the  
conventional wisdom is to not use a mac at all, but a Linux box  
instead.  If you can wait till openPBX gets going and proves itself a  
bit, then the Mac might be just fine.  My mac setup is bulletproof,   
but because of no zaptel timer (whatever the heck that is  ;~) I  
don't have music on hold, which I don't want anyhow.  No conferencing  
either.  OpenPBX or Afelio promises to resolve both these issues, but  
I haven't tried it yet.
>
> 3. The Linksys WIP300 is the cheapest alternative from a recognized
> name-brand that I've seen. Is there anything better than that at the
> same price point? Is there anything good enough that is even cheaper?
I think joining the regular digium asterisk-users list and searching  
the archives there will yield tons of information about both WIFI  
handsets and about E1 gateways.  I read that list also.  It's very  
busy, you are warned.
>
> 4. From the specs of the equipments, I see that G.729 would be a
> great codec choice, since all the equipment supports it and it
> delivers good audio quality. Also, there would be no codec
> conversion. I do not plan on using a VoIP provider now; I just want
> VoIP on my internal structure.
I am using uLaw which sounds considerably better to my ear.  If your  
audio is coming from the E1 as g729 then staying with that might be  
wise.  You will find however that there are other issues with G729 on  
the Mac,  as Digium used to have a "unsupported" codec for g729 (OSX  
PowerPC) which worked fine,  but since they updated to 1.4 there is  
no PowerPC OSX g729 codec available.  This means for example that if  
you where using g729 to record voicemail messages, and a user  
connected from a softphone without g729 support, they couldn't listen  
to there messages.

Also,  If you are in control of the entire local network for phone  
purposes I think uses ulaw or alaw is going to be easier and better  
for you.  I have a a feeling that your E1 is already using one of  
these two formats for audio.
>
> Well... I guess that's it for now. This message is really long
> already. I know I should pay for this kind of consuting service, but
> I am shamelessly asking for some free advice on the list before I
> consider putting money on this project. Sorry if I am being
> inconvenient and, if I do, please let me know.
You get what you pay for I suppose ;~)

Good Luck,
Marty