Just random data from a random user that dials into a PM w/5BRI
using an Ascend P75.
>With MP+ A can dial B and B can bring up a second line back to A if
>needed. With standard MP (RFC 1717) A dials B then A must be the one to
>add the second line.
As far as I can tell this is true. However...
I have yet to figure out how to convince the P75 to do the
automatic, "on demand" addition of the 2nd B channel when connecting
to an MP (not MP+) host like the PM. It seems to my (probably flawed)
understanding, that the P75 will only do "utilization based" add/drop of
the 2nd channel if it gets an MP+ connection.
I have two other TAs (Zyxel 2864iu & Diamond NetCommander) that are
able to do "dynamic 2nd B" calling into the PM (negotiating MP) just fine.
This leads me to believe that the P75 is just "pouting"; if it does'nt get
MP+ negotiatied, it doesn't attempt BOD.
The P75 *is* perfectly willing to establish (and maintain) a 2 channel
MP session into my ISP's PM.
Further, I've managed to setup a 2nd profile in the P75 that I can
"dial" manually when I want to add the 2nd B when calling into the
PM. To drop the 2nd B, I simply pick up the analog phone connected
to one of the P75's POTS jacks. I'm not sure this is a "supported"
operating mode of the P75 or not.
The net net of this is that the PM seems to handle add/drop of channels
in an MP connection just fine, but as far as I've been able to discover,
the P75 won't, without manual intervention, add/drop channels of
an MP connection.
>I do not believe Ascend allows more than one phone number to be set. MP+
>has a dynamic system whereby A can dial B, then query B for the number to
>dial for the second line. With MP you need a hunt group on the receiving
>end (B) because A dials the same number for each link. (Unless they allow
>multiple numbers like we do.)
I've not discovered a way to enter multiple phone numbers in a P75's
dialout profile. Back when my ISP's hunt group was not working,
I was able to use the P75 "Backup profile" feature to call a different
phone number for the 2nd channel of a 2 channel call.
>MP+ is just MP with a few extensions created by Ascend.
As far as I can tell as well.
>MP is the industry standard, and is what we support.
And it (PM MP :-) works just fine in a BOD mode with at least
two other TAs that I've tried.
>Ascend units will fall back to MP if the other end doesn't do MP+.
I've seen this as well (though I now set my dialout profile to MP
to avoid the extra LCP necotiations).
The "gotcha" that I'm stumped on is that the P75 doesn't seem
to want to do BOD at all on an MP connection.
Sorry to run on so long (but you did ask for Ascend user comments :-).
Hope this helps,
Bill