Add auto_force_rport and auto_comedia NAT options

This patch adds the auto_force_rport and auto_comedia NAT options. It
also converts the nat= setting to a list of comma-separated combinable
options: no, force_rport, comedia, auto_force_rport, and auto_comedia.
nat=yes remains as an undocumented option equal to
"force_rport,comedia". The first instance of 'yes' or 'no' in the list
stops parsing and overrides any previously set options. If an auto_*
option is specified with its non-auto_ counterpart, the auto setting
takes precedence.

This patch builds upon the patch posted to ASTERISK-17860 by JIRA user
pedro-garcia.

(closes issue ASTERISK-17860)
Review: https://reviewboard.asterisk.org/r/1698/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@354597 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Terry Wilson
2012-02-09 18:14:39 +00:00
parent 8f5c33f95a
commit e5c51ee44c
8 changed files with 286 additions and 30 deletions

View File

@@ -831,17 +831,34 @@ srvlookup=yes ; Enable DNS SRV lookups on outbound calls
; However, this is only useful if the external traffic can reach us.
; The following settings are allowed (both globally and in individual sections):
;
; nat = no ; Use rport if the remote side says to use it.
; nat = force_rport ; Force rport to always be on. (default)
; nat = yes ; Force rport to always be on and perform comedia RTP handling.
; nat = comedia ; Use rport if the remote side says to use it and perform comedia RTP handling.
; nat = no ; Do no special NAT handling other than RFC3581
; nat = force_rport ; Pretend there was an rport parameter even if there wasn't
; nat = comedia ; Send media to the port Asterisk received it from regardless
; ; of where the SDP says to send it.
; nat = auto_force_rport ; Set the force_rport option if Asterisk detects NAT (default)
; nat = auto_comedia ; Set the comedia option if Asterisk detects NAT
;
; The nat settings can be combined. For example, to set both force_rport and comedia
; one would set nat=force_rport,comedia. If any of the comma-separated options is 'no',
; Asterisk will ignore any other settings and set nat=no. If one of the "auto" settings
; is used in conjunction with its non-auto counterpart (nat=comedia,auto_comedia), then
; the non-auto option will be ignored.
;
; The RFC 3581-defined 'rport' parameter allows a client to request that Asterisk send
; SIP responses to it via the source IP and port from which the request originated
; instead of the address/port listed in the top-most Via header. This is useful if a
; client knows that it is behind a NAT and therefore cannot guess from what address/port
; its request will be sent. Asterisk will always honor the 'rport' parameter if it is
; sent. The force_rport setting causes Asterisk to always send responses back to the
; address/port from which it received requests; even if the other side doesn't support
; adding the 'rport' parameter.
;
; 'comedia RTP handling' refers to the technique of sending RTP to the port that the
; the other endpoint's RTP arrived from, and means 'connection-oriented media'. This is
; only partially related to RFC 4145 which was referred to as COMEDIA while it was in
; draft form. This method is used to accomodate endpoints that may be located behind
; NAT devices, and as such the port number they tell Asterisk to send RTP packets to
; for their media streams is not actual port number that will be used on the nearer
; NAT devices, and as such the address/port they tell Asterisk to send RTP packets to
; for their media streams is not the actual address/port that will be used on the nearer
; side of the NAT.
;
; IT IS IMPORTANT TO NOTE that if the nat setting in the general section differs from