Version2.0.78

* Added hint on how to set up MPPP with multiple numbers (via script)
* Explained why freeing B-channel on incoming phone call is difficult
This commit is contained in:
hessler 2003-07-14 19:42:49 +00:00
parent e5358e261f
commit e489f8948b
1 changed files with 32 additions and 1 deletions

View File

@ -4,7 +4,7 @@
<title>FAQ for isdn4linux
<author>Matthias Hessler (<tt><htmlurl url="mailto:hessler@isdn4linux.de" name="hessler@isdn4linux.de"></tt>)
<date>v2.0.77, 19. March 2003
<date>v2.0.78, 14. July 2003
<abstract>
If you are reading this FAQ online, you may consider downloading the whole
thing, and reading it offline (much cheaper). To download the latest
@ -4196,6 +4196,37 @@ This is a pecularity of ipppd. It tries to set MTU even for slave devices,
and the kernel can not find a corresponding network device. You can safely
ignore this information message, MPPP should work nevertheless.
<sect1> 2channel_multiplenumbers: How can I set up multiple number when
using MPPP?
<label id="2channel_multiplenumbers">
<p>
Master and slave device are fully independent of each other, except for using
the same network device to deliver packets. Setting up multiple number for
master and slave devices will result in synchronized dialout (to the same
number). Therefore it is best to give the slave device no number by default
and set up the slave with the same number as the master in some ip-up script.
<sect1> 2channel_freebchannel: How could I set up isdn4linux to free the
second B-channel if a phone call comes in?
<label id="2channel_freebchannel">
<p>
Well, this is a tough one, due to technical limits. Even if isdn4linux freed
a B-channel, the exchange would not repeat the setup call. Therefore, the
phone would not ring. The phone only signals a second incoming phone call if
you are on the phone with another call that could be suspended.
One option would be that isdn4linux frees one B-channel, then takes the call,
and transfers it to the phone via ECT (explicit call transfer); however, this
feature requires proprietary (unknown) protocol extensions, and is usually
only available behind large private exchanges - therefore not implemented
in isdn4linux.
Another option is that isdn4linux frees one B-channel, takes the call, then
suspends it. However, the user would have to know to resume it without any
phone ringing.
The most sensible option is that you handle it will a phone application
making use of isdn4linux. Possibly ant-phone could be used for such a purpose:
<tt><url url="http://www.antcom.de/"></tt>
<!-- Pecularities of your counterpart (remote device)
-->