The ISDN CPE side should not exclusively pick B channels normally.

Before this patch, Asterisk unconditionally picked B channels exclusively
on the CPE side and normally allowed alternative B channels on the network
side.  Now Asterisk does the opposite.

Reasons for the CPE side to normally not pick B channels exclusively:
*  For CPE point-to-multipoint mode (i.e. phone side), the CPE side does
not have enough information to exclusively pick B channels.  (There may be
other devices on the line.)
*  Q.931 gives preference to the network side picking B channels.
*  Some telcos require the CPE side to not pick B channels exclusively.

(closes issue #14383)
Reported by: mbrancaleoni

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@203908 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 46bc9ccec95de171ee3dfceaf804e1ec5751c6f2..d10ddb905d4f5fbfb6a79f0f8dcbd757ed0c816b 100644 (file)
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -2463,15 +2463,12 @@ static int dahdi_call(struct ast_channel *ast, char *rdest, int timeout)
                        pri_set_crv(p->pri->pri, p->call, p->channel, 0);
                }
                p->digital = IS_DIGITAL(ast->transfercapability);
-               /* Add support for exclusive override */
-               if (p->priexclusive)
+
+               /* Should the picked channel be used exclusively? */
+               if (p->priexclusive || p->pri->nodetype == PRI_NETWORK) {
                        exclusive = 1;
-               else {
-               /* otherwise, traditional behavior */
-                       if (p->pri->nodetype == PRI_NETWORK)
-                               exclusive = 0;
-                       else
-                               exclusive = 1;
+               } else {
+                       exclusive = 0;
                }
                
                pri_sr_set_channel(sr, p->bearer ? PVT_TO_CHANNEL(p->bearer) : PVT_TO_CHANNEL(p), exclusive, 1);