diff options
author | kpfleming <kpfleming@f38db490-d61c-443f-a65b-d21fe96a405b> | 2009-07-23 22:14:29 +0000 |
---|---|---|
committer | kpfleming <kpfleming@f38db490-d61c-443f-a65b-d21fe96a405b> | 2009-07-23 22:14:29 +0000 |
commit | 043301a525e5e8f6b8fe67d1f07c0d7d59989a94 (patch) | |
tree | e15c26de28ee8ac83c240be62b2f24f732fc0ced /include/asterisk/frame.h | |
parent | a1a8c370d226ca5d4abb00b428fef6abf49bbeb0 (diff) |
Merged revisions 208464 via svnmerge from
https://origsvn.digium.com/svn/asterisk/trunk
........
r208464 | kpfleming | 2009-07-23 16:57:24 -0500 (Thu, 23 Jul 2009) | 46 lines
Rework of T.38 negotiation and UDPTL API to address interoperability problems
Over the past couple of months, a number of issues with Asterisk
negotiating (and successfully completing) T.38 sessions with various
endpoints have been found. This patch attempts to address many of
them, primarily focused around ensuring that the endpoints'
MaxDatagram size is honored, and in addition by ensuring that T.38
session parameter negotiation is performed correctly according to the
ITU T.38 Recommendation.
The major changes here are:
1) T.38 applications in Asterisk (app_fax) only generate/receive IFP
packets, they do not ever work with UDPTL packets. As a result of
this, they cannot be allowed to generate packets that would overflow
the other endpoints' MaxDatagram size after the UDPTL stack adds any
error correction information. With this patch, the application is told
the maximum *IFP* size it can generate, based on a calculation using
the far end MaxDatagram size and the active error correction mode on
the T.38 session. The same is true for sending *our* MaxDatagram size
to the remote endpoint; it is computed from the value that the
application says it can accept (for a single IFP packet) combined with
the active error correction mode.
2) All treatment of T.38 session parameters as 'capabilities' in
chan_sip has been removed; these parameters are not at all like
audio/video stream capabilities. There are strict rules to follow for
computing an answer to a T.38 offer, and chan_sip now follows those
rules, using the desired parameters from the application (or channel)
that wants to accept the T.38 negotiation.
3) chan_sip now stores and forwards ast_control_t38_parameters
structures for tracking 'our' and 'their' T.38 session parameters;
this greatly simplifies negotiation, especially for pass-through
calls.
4) Since T.38 negotiation without specifying parameters or receiving
the final negotiated parameters is not very worthwhile, the
AST_CONTROL_T38 control frame has been removed. A note has been added
to UPGRADE.txt about this removal, since any out-of-tree applications
that use it will no longer function properly until they are upgraded
to use AST_CONTROL_T38_PARAMETERS.
Review: https://reviewboard.asterisk.org/r/310/
........
git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.0@208468 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'include/asterisk/frame.h')
-rw-r--r-- | include/asterisk/frame.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/include/asterisk/frame.h b/include/asterisk/frame.h index 321a935c1..9d90a083f 100644 --- a/include/asterisk/frame.h +++ b/include/asterisk/frame.h @@ -311,7 +311,7 @@ enum ast_control_frame_type { AST_CONTROL_HOLD = 16, /*!< Indicate call is placed on hold */ AST_CONTROL_UNHOLD = 17, /*!< Indicate call is left from hold */ AST_CONTROL_VIDUPDATE = 18, /*!< Indicate video frame update */ - AST_CONTROL_T38 = 19, /*!< T38 state change request/notification */ + _XXX_AST_CONTROL_T38 = 19, /*!< T38 state change request/notification \deprecated This is no longer supported. Use AST_CONTROL_T38_PARAMETERS instead. */ AST_CONTROL_SRCUPDATE = 20, /*!< Indicate source of media has changed */ AST_CONTROL_T38_PARAMETERS = 24, /*!< T38 state change request/notification with parameters */ }; @@ -339,14 +339,14 @@ enum ast_control_t38_rate_management { }; struct ast_control_t38_parameters { - enum ast_control_t38 request_response; /*!< Request or response of the T38 control frame */ - unsigned int version; /*!< Supported T.38 version */ - unsigned int max_datagram; /*!< Maximum datagram size supported */ - enum ast_control_t38_rate rate; /*!< Maximum fax rate supported */ - enum ast_control_t38_rate_management rate_management; /*!< Rate management setting */ - unsigned int fill_bit_removal:1; /*!< Set if fill bit removal should be used */ - unsigned int transcoding_mmr:1; /*!< Set if MMR transcoding should be used */ - unsigned int transcoding_jbig:1; /*!< Set if JBIG transcoding should be used */ + enum ast_control_t38 request_response; /*!< Request or response of the T38 control frame */ + unsigned int version; /*!< Supported T.38 version */ + unsigned int max_ifp; /*!< Maximum IFP size supported */ + enum ast_control_t38_rate rate; /*!< Maximum fax rate supported */ + enum ast_control_t38_rate_management rate_management; /*!< Rate management setting */ + unsigned int fill_bit_removal:1; /*!< Set if fill bit removal can be used */ + unsigned int transcoding_mmr:1; /*!< Set if MMR transcoding can be used */ + unsigned int transcoding_jbig:1; /*!< Set if JBIG transcoding can be used */ }; #define AST_SMOOTHER_FLAG_G729 (1 << 0) |