5 Replies Latest reply on Feb 18, 2016 7:15 AM by jay

    Call Admission Control TA908 Limit Particular DID's

    lordvadr New Member

      I have an inherited 908e.  It has a SIP trunk and an ISDN PRI circuit servicing a legacy PBX system.

       

      This device services a small Radio Station who regularly has call-in contests to several DID's, which are delivered via SIP.  I need a mechanism to limit inbound calls to those DID's to, say, 5 total while still allowing other DID's in unobstructed.  I've read over some documentation and examples and I just can't quite get my head around the "accept" syntax.

       

      Relevant Configuration (which is quite simple):

       

      interface t1 0/2

        tdm-group 1 timeslots 1-24 speed 64

        no shutdown

      !

      !

      interface pri 1

        isdn name-delivery proceeding

        connect t1 0/2 tdm-group 1

        digits-transferred 4

        no shutdown

      !

      !

      sip

      sip udp 5060

      no sip tcp

      !

      !

      voice feature-mode network

      voice forward-mode network

      voice call-history-depth 100

      !

      !

      voice trunk-list TRUNK

        trunk T01

        trunk T02

      !

      !

      voice trunk T01 type sip

        description "TRUNK"

        sip-server primary <scrubbed>

        outbound-proxy primary <scrubbed>

        dial-string source to

      !

      !

      voice trunk T02 type isdn

        resource-selection circular descending

        connect isdn-group 1

        early-cut-through

        modem-passthrough

        rtp delay-mode adaptive

      !

      !

      voice grouped-trunk SIP

        trunk T01

        accept $ cost 0

      !

      !

      voice grouped-trunk ISDN

        trunk T02

        accept $ cost 0

        permit list TRUNK

        !deny all other trunks

        !deny all other ani

       

      Thank you for your time.

        • Re: Call Admission Control TA908 Limit Particular DID's
          jay Employee

          CJ, unfortunately the functionality you're requesting doesn't exist. It would appear that you started trying to set up ani-lists, but those are used purely for call routing purposes and not for limiting certain number of calls. I don't know if the provider has a limiting mechanism on their end, but I would suggest checking with them to confirm. Thanks

           

          Jay

          • Re: Call Admission Control TA908 Limit Particular DID's
            lordvadr New Member

            Jay,

             

            We lab'ed this up yesterday and was able to get working what we want to work.  What are your thoughts on this config...it's just one number in the "kiddie pool" (what we're calling it) and it doesn't need to scale past a few.

             

            interface t1 0/2

              tdm-group 1 timeslots 1-8,24 speed 64

              no shutdown

             

            interface pri 1

              isdn name-delivery proceeding

              connect t1 0/2 tdm-group 1

              digits-transferred 7

              no shutdown

             

            isdn-group 1

              connect pri 1

             

            isdn-group 2

              max-channels 1 ! This group has a limit of one call

              connect pri 1

             

            voice cause-code-map from-pri 41 486

             

            voice trunk T01 type sip

              description "meta"

              sip-server primary 192.*.*.*

              outbound-proxy primary 192.*.*.*

              dial-string source to

             

            voice trunk T02 type isdn

              connect isdn-group 1

              rtp delay-mode adaptive

             

            voice trunk T03 type isdn

              connect isdn-group 2 ! send it to group 2 that has the limit

              rtp delay-mode adaptive

             

            voice grouped-trunk SIP

              trunk T01

              accept $ cost 0

             

            voice grouped-trunk ISDN1

              trunk T02

              accept $ cost 0

              reject 8005551212 ! reject the kiddie pool number(s)

             

            voice grouped-trunk ISDN2

              trunk T03 ! send it to the trunk in the group with the limit

              accept 8005551212 cost 0 ! only permit the kiddie pool number(s)

              • Re: Call Admission Control TA908 Limit Particular DID's
                jay Employee

                CJ, if you configured multiple PRIs to your PBX and can send only certain DIDs down one of the PRIs, that would work. It was the scenario you originally suggested with one pipe that couldn't. In this case, only being able to set the max calls globally on a trunk wouldn't matter, since the only calls going down that trunk are the ones you specified originally. Thanks

                  • Re: Call Admission Control TA908 Limit Particular DID's
                    lordvadr New Member

                    There's only one PRI configured...the other is shutdown.  What appears to accomplish this is that you can configure multiple isdn-group's and attach them to the same physical PRI but with different channel limits on each group.

                     

                    Now, we don't, at this point, know what exactly happens as far as channel allocation and such, but, like I said, we pointed an 8-channel pri at a test system and were able to limit calls to one DID to a single call while still allowing other calls down the same PRI...unrestricted as far as we can tell.

                     

                    For completeness sake, the original config and the lab'ed config are two different systems' config, but on each, there's only a single T1 interface configured, a single TDM group, and a single PRI.

                     

                    Anyway, so it wasn't the CAC subsystem that we used, but, unless somebody can point out what's wrong, it appears it's entirely possible to limit calls to one or more DID's to a specific number while allowing others through.

                      • Re: Call Admission Control TA908 Limit Particular DID's
                        jay Employee

                        CJ, sorry, I missed that there was only one PRI. The reason I didn't notice that is that creating multiple ISDN groups for one PRI interface has not been tested and is unsupported. If it works in your lab and you feel comfortable rolling it out, you are welcome to do so, but be cautioned that if you were to open a support ticket for any issues related to the configuration, you would be advised that we could not offer support until you moved to a single ISDN group per interface.

                         

                        That said, I don't know if your legacy PBX has a second port you could use, but if you were to implement your idea with 2 physical PRIs and the same general premise, that would be a supported configuration.

                         

                        Thanks

                         

                        Jay