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Addressing remote extension

Discussion in '3CX Phone System - General' started by rcibien, Jun 10, 2010.

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  1. rcibien

    Jan 5, 2010
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    Hi all

    I'm testing/evaluating 3CX (V8 and V9 beta) for future usage in our worldwide company group (Switzerland, Germany, Japan, South Africa) with ca. 80 employees/extensions.

    I plan a central digital receptionist (DR) offering choices for Sales, Support, Accounting, etc. All these teams would be addressed either by call queue or ring group. In special the support team consists of employees spread over different branch offices and therefore are served by multiple 3CX PBXes.

    Addressing remote extensions between multiple 3CX PBXes seems to be a major issue/problem. In one of my test environments I have two 3CX PBXes (PBX "A" with extensions 1xx and PBX "B" with extensions 2xx). A and B are coupled with a bridge. With the appropriate outbound rules it is possible to initiate calls between 1xx and 2xx extenstions (e.g. by dialing with a prefix "*" --> *201). Using dummy extensions with FORWARD ALL, it is possible to join extensions from B into a ring group on PBX A. This ring group can be directly called without any problems - all extensions (local and remote) are ringing as supposed.

    Using such a ring group (with mixed, local and remote extensions) as a target within a DR however does not work. When calling the DR and choosing the option in questions, the remote extension quickly rings, but then 3CX returns with a busy error message in the log (see at the end) while the local exteion(s) continue to ring. The extension is NOT busy because called directly or via ring group, it rings.

    Same problem with V8 and V9.

    Can anybody help on the following questions:

    - Is seems that it is not possible to see and choose remote extensions from bridged 3CX PBXes. Correct? Why not?
    - Using dummy extension, it is possible to join remote extensions into ring groups and/or call queues for direct calling. Imagine the effort to configure all needed dummy extensions all over the different 3CX PBXes. No way!
    - How to use ring groups / call queues with local and remote extensions within DR?
    - Any other ideas how to achieve my plan above with 3CX and reasonable effort?

    Any advice much appreciated.



    All server logs must be place in code brackets - this time it has been done for you - MFM

    21:58:56.855  [MS105000] C:28.1: No RTP packets were received:remoteAddr=,extAddr=,localAddr=
    21:58:56.667  [CM503003]: Call(28): Call to sip:102@ has failed; Cause: 487 Request Terminated; from IP:
    21:58:56.495  [CM503008]: Call(28): Call is terminated
    21:58:52.870  [CM503003]: Call(28): Call to sip:302@ has failed; Cause: 486 Busy Here; warning: Busy; from IP:
    21:58:52.464  [CM505004]: Bridge:[cibien] Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [3CXPhoneSystem 8.0.9481.0] PBX contact: [sip:10001@]
    21:58:52.464  [CM503002]: Call(28): Alerting sip:10001@
    21:58:51.183  [CM503025]: Call(28): Calling RingAll800:102Ext.102501302@(Ln.10000@cibien)@[Dev:sip:10001@]
    21:58:51.167  [CM503025]: Call(28): Calling RingAll800:102Ext.102501302@(Ln.10000@cibien)@[Dev:sip:102@]
    21:58:51.105  [CM503004]: Call(28): Route 1: RingAll800:102Ext.102501302@(Ln.10000@cibien)@[Dev:sip:102@,Dev:sip:10001@]
    21:58:51.089  [CM503010]: Making route(s) to <sip:800@>
    21:58:51.089  Refer: from=<sip:111@>;tag=42296f4a; to="VoIP1_101"<sip:101@>;tag=89295641; RefTo=<sip:800@>
    21:58:50.870  [MS210003] C:28.2:Answer provided. Connection(transcoding mode[unsecure]):
    21:58:50.870  [MS210001] C:28.1:Answer received. RTP connection[unsecure]:
    21:58:50.870  Remote SDP is set for legC:28.1
    21:58:50.667  [MS210002] C:28.1:Offer provided. Connection(transcoding mode):
    21:58:50.667  [MS210000] C:28.2:Offer received. RTP connection:
    21:58:50.651  Remote SDP is set for legC:28.2
    21:58:41.651  Session 4282 of leg C:28.1 is confirmed
    21:58:41.417  [CM503007]: Call(28): Device joined: sip:111@;rinstance=5b2f8d2422e840f1
    21:58:41.417  [CM503007]: Call(28): Device joined: sip:101@;rinstance=390ff890ee1f1ee9
    21:58:41.417  [MS210005] C:28.1:Answer provided. Connection(proxy mode):
    21:58:41.417  [MS210001] C:28.2:Answer received. RTP connection[unsecure]:
    21:58:41.401  Remote SDP is set for legC:28.2
    21:58:41.401  [CM505001]: Ext.111: Device info: Device Identified: [Man: 3CX Ltd.;Mod: 3CX IVR;Rev: General] Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [3CX IVR] PBX contact: [sip:111@]
    21:58:41.401  [CM503002]: Call(28): Alerting sip:111@;rinstance=5b2f8d2422e840f1
    21:58:41.183  [CM503025]: Call(28): Calling Ext:Ext.111@[Dev:sip:111@;rinstance=5b2f8d2422e840f1]
    21:58:41.183  [MS210004] C:28.2:Offer provided. Connection(proxy mode):
    21:58:41.026  [CM503004]: Call(28): Route 1: Ext:Ext.111@[Dev:sip:111@;rinstance=5b2f8d2422e840f1]
    21:58:41.026  [CM503010]: Making route(s) to <sip:111@voip1:5060>
    21:58:41.026  [MS210000] C:28.1:Offer received. RTP connection:
    21:58:41.026  Remote SDP is set for legC:28.1
    21:58:41.026  [CM505001]: Ext.101: Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [3CXPhone 4.0.12964.0] PBX contact: [sip:101@]
    21:58:40.964  [CM503001]: Call(28): Incoming call from Ext.101 to <sip:111@voip1:5060>
    21:58:40.917  [CM500002]: Info on incoming INVITE:
      INVITE sip:111@voip1:5060 SIP/2.0
      Via: SIP/2.0/UDP;branch=z9hG4bK-d8754z-d8119b4906211e67-1---d8754z-;rport=57031
      Max-Forwards: 70
      Contact: <sip:101@;rinstance=390ff890ee1f1ee9>
      To: <sip:111@voip1:5060>
      From: "3CXPhone"<sip:101@voip1:5060>;tag=1f249469
      Call-ID: YzdlNDQ1NmM2OGIxOWQ5ZTY5MmJmNDc2YzNkNmViYTM.
      CSeq: 2 INVITE
      Proxy-Authorization: Digest username="101",realm="3CXPhoneSystem",nonce="414d535c0221d4f057:a137baa1a64ea1e94069b561be9d3e67",uri="sip:111@voip1:5060",response="052efbc8aaf024afef537a3549337dba",algorithm=MD5
      Supported: replaces
      User-Agent: 3CXPhone 4.0.12964.0
      Content-Length: 0
  2. mfm

    mfm Active Member

    Mar 4, 2010
    Likes Received:

    You' ve got urself in quite deep allready, well lets see how we can help you further.

    Lets talk first about your intial problem, the brige for whatever reason is saying that the extension is busy, which is a bit strange. To diagnose further I would need to see both PBX Logs.

    Secondly is there any particular reason you need a PBX at all locations rather then having one main manageable PBX and distributing external extensions out to every department?

    - It is the way it is programmed to be at this point, there is no reason but the feature is has yet to be implemented, but im not sure whether there is a plan to do so with the upcoming release.

    -Youve made it more complex then needs be, if you need those extension to be on both PBX, make the phone use 2 extensions, 1 is the internal one and the other is the external one, this leave a more manageable phones.

    -- Failed to understand question

    -- Your place can be achieved but you might have to rething your strategy.

    Feel free to bombard with more questions :)
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  3. rcibien

    Jan 5, 2010
    Likes Received:
    Hi mfm

    The bridge just says "busy" when using DR. Otherwise the remote extension can be called no matter whether direct (via outbound rule and prefix) or dummy extension or via ring group. Just the DR does not work.

    As written, our branch offices are in CH, DE, SA and JP. In my eyes it does not make any sense in having all extensions connecting to the PBX in the Swiss HQ as well as connecting all VoIP/SIP providers (one for each country) to the same single point of failure. In such an architecture, traffic goes over the network twice and furthermore, everybody relies on Swiss internet access and infrastructure. Even local phone calls would have to pass thru Switzerland. Another example: Our customer hotline is located in an additional decentral branch office in Switzerland. With a single PBX configuration, the hotline would be dead if the internet line to the headquarter breaks. So, I even need a proper PBX at the hotline office with a failover PSTN connection. That's why I planned to have multiple PBXes with bridges in between.

    Your recommendation: Use 2-extension phones: I'm a newbee in VoIP, but is this really state-of-the-art of VoIP configuration? This leads to tremendous overhead in phone configuration/provisioning and in documenting these configurations for an issue that could/should be done centraly at the PBX. Furthermore, networktraffic becomes more complex as there are more many-to-many connections instead of centralized PBX-to-PBX traffic. Last but not least: What about soft phones connecting to mulitiple extensions at the same time? As far as I know, the 3CX soft phone is not able to do so...

    Question not understood: I'm looking for a solution for doing such a configuration (see attached picture).

    Please note: Extension numbers, etc. do not reflect test environment in log file.

    Question: Could this behaviour be caused by a restricted demo license key?

    Product: 3CXPSDEMO
    Version: 9
    Number of Simultaneous calls: 3
    Number of G729 Channels: 0


    Attached Files:

  4. mtnman

    Sep 16, 2009
    Likes Received:
    Could the issue be that you have the PBX configured to have users dial a * before the extension? If you temporarily set up the PBX to send calls for 2xx via your tie connection to the other site, it may work. I certainly haven't played much with the system or bridging two 3cx systems, but from reading what you posted, not having the * may be the issue.
  5. rcibien

    Jan 5, 2010
    Likes Received:

    No, the problem is not a missing "*". You're right, I configured "*" as a prefix in order to dial so-called remote extension (other 3CX PBX extensions). This is a temporary configuration as there were conflicts with the pre-defined dialing codes in 3CX (which I changed to # instead of *).


    • *201 uses an outgoing rule to PBX B, extension 201 --> Dialing *201 works fine.
    • 501 is a dummy extension with FORWARD ALL to external number *201 --> Dialing 501 works fine, too.
    • 801 is a dial group with RING ALL where 501 is a member --> Dialing 801 works fine, all local extensions as well as remote extension 201 ring.
    • DR - Option 3 calls ring group 801 --> does not work :-(

    Makes no sense, does it?

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