Passing Custom Metadata with X-B-ext SIP Headers

CommPeak provides three pass-through custom Session Initiation Protocol (SIP) headers - X-B-ext1, X-B-ext2, and X-B-ext3 - that carry your own metadata through your calls end to end. Use them for correlation IDs, routing hints, or any application data you need to survive the call path.

Available headers

Add any of the three headers to your SIP messages:

X-B-ext1: <your-value>
X-B-ext2: <your-value>
X-B-ext3: <your-value>

Where the headers are carried

• Origination (inbound calls to your DID): if an incoming call to your CommPeak Direct Inward Dialing DID) number carries X-B-ext1, X-B-ext2, or X-B-ext3, CommPeak forwards them to the leg delivered to your endpoint.
• SIP REFER transfers: When you transfer an outgoing call to a CommPeak DID, CommPeak copies any X-B-ext1, X-B-ext2, or X-B-ext3 headers present in your initial INVITE and replicates them in the outbound INVITE sent to the DID. For the transfer flow itself, see the Transferring In-Progress Call to a CommPeak DID page.

Usage rules

• Three slots only. X-B-ext1, X-B-ext2, and X-B-ext3 are the exact header names (case-insensitive). Other X- headers are not passed through.
• Present-only forwarding. A header you do not send is not forwarded - there is no default value.
• Keep values simple. Plain alphanumeric tokens are safest. Avoid SIP and URI special characters and control characters, which may be altered or dropped in transit.

EXAMPLE

The initial outbound SIP INVITE request to your lead carrying the metadata, which will also be delivered via SIP REFER to the CommPeak DID:

INVITE sip:… SIP/2.0
…
X-B-ext1: order-12345
X-B-ext2: agent-77
X-B-ext3: campaign-spring

For DID or transfer configuration requests, submit a ticket to CommPeak support.