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How do you add custom outbound SIP Headers

  • 1.  How do you add custom outbound SIP Headers

    Posted 02-05-2021 15:26
    2018 R2 P35
    I'm currently reading inbound SIP headers but I'm needing to set values for calls transferred outside of the system.  I'm not seeing what attribute to set when a transfer when making a transfer.  I've tried adding the header name to the line config for Transferred Headers and Call Attribute Headers (which is what is set to read inbound).  I'm just missing a step somewhere.​

    Matthew Williams
    Regions Bank

  • 2.  RE: How do you add custom outbound SIP Headers

    Posted 02-07-2021 04:47
    We use attribute Eic_ISDNUUIData in my environment with Enable sending SIP REFER Messages enabled on a line level for transfer outs.  I've seen sip headers work internally, but never tried externally because we are not true sip end to end yet.....  I assume you have to set the attribute on the transferred call's Interaction ID....EicSIPHeader_"HeadName"

    John Sweet
    TSYS - Interactive Services

  • 3.  RE: How do you add custom outbound SIP Headers

    Posted 02-08-2021 12:58
    I can set EicSIPHeader_"HeaderName" on the call that is transferred​.  I thought all I had to other than that was set in the "HeaderName" in the header section on the line property but I'm not seeing the header in the logs or when running wireshark on the transferred call.

    Matthew Williams

  • 4.  RE: How do you add custom outbound SIP Headers

    Posted 06-15-2021 07:30
    Did you ever make this work? I am struggling to setting Outbound Sip Headers with the extended place call toolstep. The only helpful link I have found was this:


    Nate Bennett wrote:
    Call Attribute: Eic_UserToUserData Snip from the sip developer application notes.
    Eic_UserToUserData syntax: [name=value[;name=value]*] Note: name and value can not contain any double quotes. Note: name must start with uu_. Outbound Logic The value in the call attribute Eic_UserToUserData will be put in the ININAttr header in the following SIP messages: • outbound INVITEs • outbound 302 responses (for blind transfers) • outbound REFERs without replaces (for blind transfers) 
    Part 1 Set the attribute Eic_UserToUserData with your string of header/values. "uu_H1=SomeValue;uu_h2=someMoreValue" As the notes state this will append as: ININAttr: "uu_H1=SomeValue;uu_h2=someMoreValue" Part 2 Since this is an off-premise transfer the messages will have to traverse the SBC. It is at this point we will leverage the SBC to modify the headers to remove the ININAttr header and insert our own headers with the respective values. So in the end we have now presented a REFER message with the appropriate requested headers to the far end. We also maintained strict typing and did not revert all upper case to lower. It does add a level of complexity with us not being able to do it all on the I3 platform. However thankfully it will not be to bad to maintain.

    That actually works but I would like to find a way without HMR on our SBC. Please let me know if you have found a solution.


    Christopher Drieschner
    Bosch Security Systems, Inc.