[Asterisk-Users] 3 x TDM400P in one PC ??

[Walt Reed]

Reformatted top-posting...

On Fri, May 06, 2005 at 08:30:52AM -0600, Andres Paglayan said:
> Walt Reed wrote:
> >On Fri, May 06, 2005 at 10:25:24PM +1000, Joerg Wleklik said:
> >>On Fri, 6 May 2005 22:10, Eric Wieling aka ManxPower wrote:
> >>>Joerg Wleklik wrote:
> >>>
> >>>>Does anybody have experiences with plugging 3 TDM400P cards in one PC??
> >>>>
> >>>If you need 12 ports then you should use a T-1 card and a Channel Bank.
> >>>
> >>That would be easy, but......
> >>
> >>I have 8 analogue lines incoming right now and changing the phone number 
> >>is not an option (costs for advertising). This lines go right now into an 
> >>analogue PBX. A new building will get IP-Phones connected to an asterisk 
> >>box.
> >>The idea is to take the incoming calls in the asterisk, route to the new 
> >>building via IP and serve the old PBX with 4 analogue lines. 
> >
> >That's what the channel bank does. 
> >
> >The other reason you want to use a T1 card over multiple TDM400 cards is
> >that the 3 TDM cards will generate 3 times the number of interrups, and
> >likely have interrupt sharing problems. Good channel banks also are
> >going to be much less prone to have echo problems. You also will have
> >room for expansion.
> >
> >BTW, if you went with a new T1/PRI to the telco, you can probably have
> >your old numbers forwareded / migrated.

> Why the channel bank if he will be routing extensions to ip phones?
> The T-1 card should suffice if he isn't serving analog extensions.
> Thats $600 (t1) instead of ~ $1000.(3 x 3?? tdm400p)
> line cost wise 12 channels on a t1 should be cheaper than 8 pots.

Because he STILL needs analog lines for the legacy PBX (read above), and
he does NOT have a T1 now - just POTS PSTN lines. That's 12 analog
ports needed.

Now if he were to convert to a T1 (or E1 / PRI) for his PSTN connection
(as I mentioned,) then he could get a couple cheap Sipura's for the
legacy PBX and forget the channel bank. Depends on what he can get for
T1/E1/PRI pricing (8 channels is usually not very cost effective.)