Outbound calls on VoIP lines

When placing an outgoing call the IP address or domain of the Switch/PBX which will be routing the call needs to be specified.

For example, when dialing another extension on the VoIP Switch/PBX the number dialed would be in the format: extension@ip_address_of_voip_switch



According to how the VoIP switch is set up, the "extension" could also be an external phone number.

when dialing through a VoIP provider, often the VoIP provider's SIP server domain/address needs to be specified. eg:


You can also just specify the IP address by itself, if you know the IP address of the SIP device that you want to dial directly. eg:

The Network Adapter's DNS settings must not have any uncontactable DNS entries.
Otherwise the domain names used on outgoing calls may not be resolved,
and DNS NAPTR record queries done as part of responding with Authentication details will fail.
If HMP is unable to perform the DNS NAPTR record query, then a domain-name addressed outgoing call that requires Authentication will fail.


CallerID / "From:" field

When making an outgoing call on a VoIP line it is usually necessary to specify the CallerID to be used on the outgoing call. This advises the switch relaying the VoIP call as to which account/subscriber is making the call.

The CallerID is set in the SIP header's "From:" field.

The CallerID ("From:" field) on outgoing calls can be specified using the <CallerID> tag in the call's Options, in this format:


eg: to place a call through a PBX which is installed on a server with IP of, and with which the user/extension 2000 has been registered by VoiceGuide, the following entry would need to be included in the Options field:


Sometimes just the user ID (or the registered telephone number) is sufficient, eg:



And to place a call through a VoIP provider with which the account was registered by VoiceGuide, an entry that includes the domain name of the provider needs to be used. eg: with CallCentric, this would need to be used:


and with Skype SIP Connect, a CallerID definition similar to this would need to be used:



In the Outbound Call Loader app the Call Options are set in the "Call Options" text box, located at the bottom of the "Script" page.

If loading the calls using the XML method th Call Options are set in the <CallOptions> field.



VoIP switch will often require to authenticate the user before allowing the outbound call to be made.

IP-based authentication does not require any additional configuration in VoiceGuide.

If Digest authentication is used then it is necessary to specify the Registration and Authentication parameters.
Please see here: VoIP Line Registraton


User Specified Headers

If specific headers need to be added/modified in the outgoing SIP INVITE packet then these can also be specified in the call's options when loading the outgoing call.
To add a SIP header a "<sip-header>" entry needs to be specified as part of the call's options.
eg: to add a "MyHeader" header, this entry could be added:

<sip-header>MyHeader: "somevalue" <sip:123456@sip.router.com></sip-header>

"sip-session-expires" and "sip-min-se" entries can also be specified like this:


(or these header entries could be just added using the "<sip-header>" approach)


Multiple headers can be specified. Below is a valid options entry:

<sip-header>Remote-Part-ID: "Flowroute" <sip:123412341234@sip.flowroute.com;party=calling;screen=yes;privacy=on</sip-header>
<sip-header>X-Tag: mySpecialCallTag123</sip-header>
<sip-header>Diversion: <sip:333444555@sip.mycarrier.com></sip-header>


Where to set Call Options

Call options can be set the "Call Options" text box in the Outbound Call Loader app, or in the <CallOptions> field in the OutDial XML file, like this:

  <sip-header>Remote-Part-ID: "Flowroute" <sip:123412341234@sip.flowroute.com;party=calling;screen=yes;privacy=on</sip-header>
  <sip-header>X-Tag: mySpecialCallTag123</sip-header>
  <sip-header>Diversion: <sip:333444555@sip.mycarrier.com></sip-header>


WireShark can be used to verify that the headers have been set in the outgoing INVITE packets as expected.



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