prefixkit RU

VoIP & telephony

SIP server check

Check whether a SIP server, PBX or trunk answers: DNS SRV records, TCP or TLS connection, the reply to SIP OPTIONS, the server’s User-Agent and supported methods.

Without a port we use the domain’s SRV record, or 5060 (TCP) / 5061 (TLS).

How it works

We connect to the server and send a SIP OPTIONS request: the same “ping” PBXs and proxies use to check trunks (qualify in Asterisk, keepalive in Kamailio). Any reply, even 401 or 403, means the SIP stack is alive. The reply also reveals the server software (the Server or User-Agent header) and the methods it supports.

Calls connect but have problems? Load a capture into the pcap analyzer. Response codes are explained in the SIP code reference.

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