[asterisk-users] FAX Issues

[Steve Totaro]

On Tue, Aug 9, 2011 at 8:31 PM, Lee Howard <faxguy at howardsilvan.com> wrote:
> Steve Totaro wrote:
>>
>> On Tue, Aug 9, 2011 at 7:22 PM, Lee Howard <faxguy at howardsilvan.com>
>> wrote:
>>
>>>
>>> Ryan McGuire wrote:
>>>
>>>>
>>>> Unless your network is under load and you are seeing dropped packets
>>>> and high jitter, I would absolutely not do T.38. The cheapest and
>>>> easiest approach that I have found is to buy yourself an FXS gateway
>>>> and just make sure you are using ulaw.
>>>>
>>>
>>> As SIP is usually running over UDP/IP it doesn't take much to produce
>>> dropped packets.  Dropped packets mean lost audio which means lost data
>>> and
>>> possible demodulation difficulties for the modems.  If you're in an
>>> environment where dropped UDP packets don't occur you're in a very rare
>>> scenario.
>>>
>>
>> I suppose you are talking about from the provider and not on the LAN?
>>
>
> You certainly can (and usually will) have UDP packet loss on an uncontrolled
> LAN.

Then you should be fired for not controlling your LAN.

>
>> At Equinix in Ashburn VA, I have never had a dropped packet via the
>> crossconnect from our cage to Level3's cage.  Sub ms pings.  Putting
>> the primary PBX in Equinix and a 100meg speed for all VoIP calls in
>> our out.  100meg DIA and 100meg layer 2 fiber to corporate.
>
> I have no reason to doubt your claims, but if this is true, then your
> arrangement there clearly mitigates the likelihood of UDP packet loss.
>  Nevertheless, this arrangement is not something that the typical user who
> asks "how do I fax over SIP/VoIP" is going to have.  Without being very
> clear about the environment and explaining the pitfalls of not following
> your example exactly, you're not doing them any favors by encouraging them
> to attempt it in their environment.

I don't care what you doubt or not.  I engineered it, Got the
contracts signed, provisioned, setup BGP, got all that cleared with
the steering committee.

I do not assume anything about anyone and cannot define a typical
user.  That is making as ass out of you and me.

I encourage everyone to attempt and test everything!  Not put it in
production without some reasonable testing.

>
> For every one user who I've ever heard from saying that they have reliable
> G.711 faxing over their SIP channels I've heard from a dozen who don't.

Roger That.  That is why I advise clients it is not the best way to go.

>
> Thanks,
>
> Lee.

He came in giving no details about his setup.  Now I see it is 1000 phones.

I guess you don't care to read threads, and like to jump in the middle
not knowing what you are talking about.

I said that there is really no good way to handle faxes with Asterisk
except with a T1, IAXmodem, and Hylafax.

I bought fax for Asterisk when migrating to an all SIP world and it
was a dismal failure and Digium didn't even have anyone that could
explain any of the stats or problems I had.  I paid for it so I didn't
have to screw around and finally I just took a refund and a big dent
as far as the companies opinion of me.

I wanted to try the 1.2 asterisk fork and that other project that came
from the fact that Asterisk has deadlock issues and a whole cross
platform rewrite has been done.

Thanks,
Steve Totaro