Voip Think- Voice over IP - Asterisk and SER - SIP IAX and H323

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  • VoIP Protocols

  • Telephones

  • QoS (Quality of Service)

  • Codecs

  • Asterisk

  • 3CX PBX

  • SER (Sip Express Router)

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      IAX protocol  

        Architecture   Messages   Type of frames   Frames field values   SIP vs IAX  

    IAX F Frames Values

    The Type Frame field of F frames along with the subclass field determines the function of the package that has been sent or received.They are the control signaling messages.

    The Type Frame field is a set of 8 bits (1 byte) and the main values that can take are shown in the following table:

    Table 1. Main values of the "Type Frame" field of F frames or Full Frame

    "type frame" value Description Details
    00000001 DTMF To send DTMF digits
    00000002 Voice Data Subclass field show the audio codec used. See table 2.
    00000003 Video Subclass field show the video codec used.
    00000004 Control Provide session control. They refer to control of the devices connected to the IAX endpoint. Subclass field show the specific control message. See table 3.
    00000005 No usado  
    00000006 IAX Control Provide IAX protocol specific endpoint management. They are used to manage IAX protocol interactions that are generally independent of the type of endpoints. Subclass field show the specific IAX control message. See table 4.
    00000007 Text  
    00000008 Image  
    00000009 HTML  

    Table 2. Meaning of the subclass values for Frame Type = "0x02" (voice data)

    Subclass Value (Type Frame =0x02) Description (codec used in the convesation)
    0x0001 G.723.1
    0x0002 GSM
    0x0004 G.711 u (u-law)
    0x0008 G.711 a (a-law)
    0x0080 LPC10
    0x0100 G.729
    0x0200 Speex
    0x0400 iLBC

    Table 3. Meaning of the subclass values for Frame Type = "0x04" (control)

    Subclass Value (Type Frame =0x04) Description
    0x01 Hangup
    0x02 Ring
    0x03 Ringing (ringback)
    0x04 Answer
    0x05 Busy Condition
    0x08 Congestion Condition
    0x0e Call Progress

    Table 4. Meaning of the subclass values for Frame Type = "0x06" (IAX control)

    Subclass Value (Type Frame =0x05) Description Details        
    0x01 NEW Initiate a new call   0x10 REGREJ Registration reject
    0x02 PING Ping request   0x11 REGREL Registration release
    0x03 PONG Ping reply   0x12 VNAK Video/Voice retransmit request
    0x04 ACK Acknowledgement   0x13 DPREQ Dialplan request
    0x05 HANGUP Initiate call teardown   0x14 DPREP Dialplan response
    0x06 REJECT Reject   0x15 DIAL Dial
    0x07 ACCEPT Accepted   0x16 TXREQ Transfer request
    0x08 AUTHREQ Authentication request   0x17 TXCNT Transfer connect
    0x09 AUTHREP Authentication reply   0x18 TXACC Transfer accept
    0x0a INVAL Invalid call   0x19 TXREADY Transfer ready
    0x0b LAGRQ Lag request   0x1a TXREL Transfer release
    0x0c LAGRP Lag reply   0x1b TXREJ Transfer reject
    0x0d REGREQ Registration request   0x1c QUELCH Halt audio/video transmission
    0x0e REGAUTH Registration authenticate   0x1d UNQUELCH Resume audio/video transmission
    0x0f REGACK Registration acknowledgement   0x20 MWI Message waiting indication
            0x21 UNSUPPORT Unsupported message


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