Free tool

SIP call inspector

Call our number from your PBX, softphone, or mobile. Get a reconstructed SIP ladder diagram, caller ID, attestation level, and carrier details — instantly.

// Call this number to inspect your SIP headers

+60 16 299 5263

Malaysian DID · Works from any SIP client, PBX, or mobile · Results appear below

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Make a call above, then click Start listening to see your results.
📊 SIP Ladder
🔬 Raw data
Note: This is a reconstructed SIP ladder based on data captured by Twilio's webhook. Raw SIP headers such as Via, Contact, User-Agent, and Route are stripped by Twilio's SBC and are not available. Annotated values reflect what your system actually presented to the network.
Headers not shown: Via, Contact, User-Agent, Route, Record-Route, Max-Forwards, Allow, Supported, and Content-Type are stripped by Twilio's Session Border Controller before the webhook is fired. This is standard behaviour for any CPaaS provider. To inspect raw SIP, use a SIP packet capture (e.g. Wireshark, sngrep) on your own network.
// What this tool captures
Caller ID
The number your system presents as the SIP From header
Caller Name
CNAM display name if your carrier sends it
STIR/SHAKEN
Attestation level A, B, C, failed, or none
SIP Call-ID
The SIP Call-ID header from your INVITE
SIP Source IP
IP address your SIP INVITE originated from
Forwarded From
Original number if the call was forwarded
Carrier
Carrier and line type detected by Twilio
Geographic
Country and city inferred from the number