| SIP Express Router v0.8.8 - Developer's Guide | ||
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The SL module provide possibilities to send stateless replies for the current request. Additional, a filter function is available for checking the ACK requests generated by sending a SL reply to a INVITE req. Also, offers the possibility to send explanatory SL replies in case of an internal error.
For the SL module to be able to recognize the ACKs generated by INVITE's replies sent by itself, all the sent replies will have attached to TO header a "tag" param. having a unique value (that was random generated at ser startup).When an ACK is received, the TO tag param tag is checked if corresponds - all UAS MUST copy the TO tag from replies into ACK requests! TO speed up the filtering process, the module uses a timeout mechanism. When a reply is sent, a timer us set. As time as the timer is valid, The incoming ACK requests will be checked using TO tag value Once the timer expires, all the ACK are let through - a long time passed till it sent a reply, so it does not expect any ACK that have to be blocked.
None.
For the current request, a reply is sent back having the given code and text reason. The reply is sent stateless, totally independent of the Transaction module and with no retranssmision for the INVITE's replies.
code - Reply code to be used.
text_reason - Reason phrase to be used.
Identifies and blocks the ACK requests generated by INVITE's replies sent using the sl_send_reply() or sl_send_error() functions.
s1 - Not used.
s2 - Not used.
Identifies and blocks the ACK requests generated by INVITE's replies sent using the sl_send_reply() or sl_send_error() functions.
s1 - Not used.
s2 - Not used.
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