SIP protocol implementation written in PHP

0.7.1 2023-05-22 14:24 UTC

This package is auto-updated.

Last update: 2024-05-22 16:47:44 UTC



PHP SIP Parsing/Rendering Library

RFC 3261 compliant SIP parsing and rendering library for PHP 7.4.

CI Status Psalm Type Coverage Latest Stable Version Installs on Packagist Test Coverage Maintainability License


SIP Message Parsing

Once installed, you can parse SIP messages right away as follows:

 * $text holds your SIP message as a string, for example
 * $text = 'REGISTER sip: SIP/2.0 /.../';
$message = \RTCKit\SIP\Message::parse($text);

/* Outputs "RTCKit\SIP\Request" */
echo get_class($message) . PHP_EOL;

/* Outputs something similar to:
 * Protocol version:   SIP/2.0
 * Request method:     REGISTER
 * Request URI:        sip:
 * Via:      
 * Via branch:         z9hG4bK.eAV4o0nXr
 * From scheme:        sip
 * From user:          buzz
 * From host:
 * From tag:           SFJbQ2oWh
 * To scheme:          sip
 * To user:            buzz
 * To host:  
 * Sequence number:    20
 * Call ID:            ob0EYyuyC0
printf("Protocol version:   %s" . PHP_EOL, $message->version);
printf("Request method:     %s" . PHP_EOL, $message->method);
printf("Request URI:        %s" . PHP_EOL, $message->uri);
printf("Via:                %s" . PHP_EOL, $message->via->values[0]->host);
printf("Via branch:         %s" . PHP_EOL, $message->via->values[0]->branch);
printf("From scheme:        %s" . PHP_EOL, $request->from->uri->scheme);
printf("From user:          %s" . PHP_EOL, $request->from->uri->user);
printf("From host:          %s" . PHP_EOL, $request->from->uri->host);
printf("From tag:           %s" . PHP_EOL, $request->from->tag);
printf("To scheme:          %s" . PHP_EOL, $request->to->uri->scheme);
printf("To user:            %s" . PHP_EOL, $request->to->uri->user);
printf("To host:            %s" . PHP_EOL, $request->to->uri->host);
printf("Sequence number:    %s" . PHP_EOL, $message->cSeq->sequence);
printf("Call ID:            %s" . PHP_EOL, $message->callId->value);

SIP Message Rendering

Rendering is the opposite action of parsing; for example, let's prepare a 200 OK response for a REGISTER request:

$response = new \RTCKit\SIP\Response;
$response->version = 'SIP/2.0';
$response->code = 200;

$response->via = new \RTCKit\SIP\Header\ViaHeader;
$response->via->values[0] = new \RTCKit\SIP\Header\ViaValue;
$response->via->values[0]->protocol = 'SIP';
$response->via->values[0]->version = '2.0';
$response->via->values[0]->transport = 'UDP';
$response->via->values[0]->host = '';
$response->via->values[0]->branch = 'z9hG4bK.eAV4o0nXr';

$response->from = new \RTCKit\SIP\Header\NameAddrHeader;
$response->from->uri = new \RTCKit\SIP\URI;
$response->from->uri->scheme = 'sip';
$response->from->uri->user = 'buzz';
$response->from->uri->host = '';
$response->from->tag = 'SFJbQ2oWh';

$response->to = new \RTCKit\SIP\Header\NameAddrHeader;
$response->to->uri = new \RTCKit\SIP\URI;
$response->to->uri->scheme = 'sip';
$response->to->uri->user = 'buzz';
$response->to->uri->host = '';
$response->to->tag = '8cQtUyH6N5N9K';

$response->cSeq = new \RTCKit\SIP\Header\CSeqHeader;
$response->cSeq->sequence = 20;
$response->cSeq->method = 'REGISTER';

$response->callId = new \RTCKit\SIP\Header\CallIdHeader;
$response->callId->value = 'ob0EYyuyC0';

$response->maxForwards = new \RTCKit\SIP\Header\ScalarHeader;
$response->maxForwards->value = 70;

$response->contact = new \RTCKit\SIP\Header\ContactHeader;
$response->contact->values[0] = new \RTCKit\SIP\Header\ContactValue;
$response->contact->values[0]->uri = new \RTCKit\SIP\URI;
$response->contact->values[0]->uri->scheme = 'sip';
$response->contact->values[0]->uri->user = 'buzz';
$response->contact->values[0]->uri->host = '';
$response->contact->values[0]->uri->port = 5050;
$response->contact->values[0]->uri->transport = 'udp';
$response->contact->values[0]->expires = 3600;

$response->userAgent = new \RTCKit\SIP\Header\Header;
$response->userAgent->values[0] = 'MyDeskPhone/1.0.0';

/* Outputs:
 * SIP/2.0 200 OK
 * Via: SIP/2.0/UDP;branch=z9hG4bK.eAV4o0nXr
 * From: <sip:buzz@>;tag=SFJbQ2oWh
 * To: <sip:buzz@>;tag=8cQtUyH6N5N9K
 * Contact: <sip:buzz@;transport=udp>;expires=3600
 * Call-ID: ob0EYyuyC0
 * CSeq: 20 REGISTER
 * Max-Forwards: 70
 * User-Agent: MyDeskPhone/1.0.0
echo $response->render();

SIP Message Stream Parsing

If your use case involves a continuous data stream rather than individual messages, the StreamParser class can help; this is particularly useful for analyzing SIP trace files or packet captures, parsing SIP traffic over TCP etc.

/* Instantiate the Stream Parser */
$parser = new \RTCKit\SIP\StreamParser;

$fp = fopen(/.../);

while (!feof($fp)) {
    $bytes = fread($fp, 256);

    /* The actual input string ($bytes) can be retrieved from any stream-like source */
    if ($parser->process($bytes, $messages) === \RTCKit\SIP\StreamParser::SUCCESS) {
        foreach ($messages as $message) {
             * $message is either a Request or a Response object, using
             * the same structure as messages returned by Message::parse()

Lastly, the provided examples are a good starting point.


RTCKit\SIP is compatible with PHP 7.4+ and has no external library and extension dependencies.


You can add the library as project dependency using Composer:

composer require rtckit/sip

If you only need the library during development, for instance when used in your test suite, then you should add it as a development-only dependency:

composer require --dev rtckit/sip


To run the test suite, clone this repository and then install dependencies via Composer:

composer install

Then, go to the project root and run:

php -d memory_limit=-1 ./vendor/bin/phpunit -c ./etc/phpunit.xml.dist

Static Analysis

In order to ensure high code quality, RTCKit\SIP uses PHPStan and Psalm:

php -d memory_limit=-1 ./vendor/bin/phpstan analyse -c ./etc/phpstan.neon -n -vvv --ansi --level=max src
php -d memory_limit=-1 ./vendor/bin/psalm --config=./etc/psalm.xml


MIT, see LICENSE file.



Bug reports (and small patches) can be submitted via the issue tracker. Forking the repository and submitting a Pull Request is preferred for substantial patches.