[asterisk-biz] Big VoIP switches

[Alex Pilosov]

On Wed, 25 Jul 2007, Alex Balashov wrote:

> On Wed, 25 Jul 2007, Alex Pilosov wrote:
> 
> > The ghetto fabulous solution of course would be Lucent TNT/APX, controlled
> > with ser. APX controlled by a proper h248/sigtran softswitch would
> > probably have lowest price/ghettoness for certain cases.
> >
> > (each apx8000 can take 2800 ds0 ports with dsps etc, for 1000 DS1s
> > you'd need 10 APX8000s)
> 
>    I am amused by and to some extent empathetic with your maxim, but I
> would be curious if you could flesh out your precise reasons for the
> belief that this is a "ghetto fabulous" approach.
> 
>    Do you know what Level3--which, by most accounts has a decidedly
> non-ghetto luster--uses for their media gateway farms, at least on their
> traditional pre-Sonus voice network?
a) whether (3) is ghetto or not is in the eye of beholder. Certainly, some 
pieces of their network/gear are more ghetto than others. 

b) i'd think the 'ghetto fabulousness' is self-evident, however, for those 
who do not hold these truths to be self-evident, explanation:

1) TNT has been EOL'd in 2003

2) APX isn't EOL'd, but it is a "bastard child" for lucent - who doesn't 
seem to be too interested in pushing it.

3) TAOS is still being maintained, however, to have a legit copy, you 
need a support contract, which is obscenely expensive and negates benefit 
of using cheap TNT/APX. (Really, they are only cheap because some other 
sucker bought them, got disgusted and threw it out).

4) TAOS is buggy as hell, and is clearly feature-lacking compared to (say)
IOS on 5800s. 

5) There's tiny installed base, and level of support from lucent is
minimal even if you pay obscene rates listed above.

6) TAOS 10 preferred H323 for control of q931 and IPDC for control of
ISUP.

7) IPDC is very proprietary. Softswitches are *rare* and *expensive*. The
'midrange' softswitch vendors don't support it, and you are left with only
Metaswitch and Telica (and lucent ASG, which is a separate story
altogether).

8) TAOS 11 prefers SIP for control of q931. Problem is, their mapping of
SIP into Q931 is extremely limited as far as features - you can't request
certain q.931 fields to be filled in using SIP messages.

9) TAOS 12 prefers h248 and SIGTRAN for control of both q931 and isup
traffic. Now, that is actually sensible solution (to backhaul signaling
traffic to mgc and let it deal with it), and h248/sigtran are
non-proprietary. There are some midrange switches that support
h.248/sigtran, so this may yet be some way of using them in a reasonable 
manner.


c) as i stated above, use of TNT/APX for simple media conversion (ip/tdm)
is actually sensible and while being ghetto fabulous, is fine. there isn't 
that much that needs to be done and the hardware is perfectly capable of 
doing it.