Supported

option-tag

precondition

Message-body

The following SDP types and values.

Session description:

– v=0

– o=(username) (sess-id) (sess-version) IN (addrtype) (unicast-address for UE)

– s=(session name)

– c=IN (addrtype) (connection-address for UE) [Note 1]

– b=AS: (bandwidth-value)

Time description:

– t= (start-time) (stop-time)

Media description:

– m=audio (transport port) RTP/AVP (fmt)

– c=IN (addrtype) (connection-address for UE) [Note 1]

– b=AS: (bandwidth-value)

– b=RS: (bandwidth-value) [Note 2]

– b=RR: (bandwidth-value) [Note 2]

Attributes for media:

– a=rtpmap: (payload type) AMR/8000 [Note 3]

– a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 4, 5]

– a=rtpmap: (payload type) telephone-event/8000

– a=ptime:20

– a=maxptime:240

Attributes for preconditions:

– a=curr:qos local none

– a=curr:qos remote none

– a=des:qos mandatory local sendrecv

– a=des:qos optional remote sendrecv

Note 1: At least one "c=" field shall be present.

Note 2: The RR value must be greater than 0. The RS value can be any value.

Note 3: The AMR channel number shall be “/1” or omitted.

Note 4: The max-red values from 0 to 220 are allowed.

Note 5: The parameters mode-set, mode-change-period, mode-change-neighbor, crc, robust-sorting and interleaving shall not be included.

Require

option-tag

precondition

Message-body

The following SDP types and values.

Session description:

– v=0

– o=- 1111111111 1111111111 IN (addrtype) (unicast-address for SS)

– s=-

– c=IN (addrtype) (connection-address for SS)

– b=AS:37

Time description:

– t=0 0

Media description:

– m=audio (transport port) RTP/AVP (fmt) [Note 1, 2]

– b=AS:37

– b=RS: (bandwidth-value) [Note 3]

– b=RR: (bandwidth-value) [Note 3]

Attributes for media:

– a=rtpmap: (payload type) AMR/8000/1 [Note 1]

– a=fmtp: (format) mode-change-capability=2; max-red=220 [Note 1]

– a=ptime:20

– a=maxptime:240

Attributes for preconditions:

– a=curr:qos local none

– a=curr:qos remote none

– a=des:qos mandatory local sendrecv

– a=des:qos mandatory remote sendrecv

– a=conf:qos remote sendrecv

Note 1: The value for fmt, payload type (AMR) and format is copied from step 2.

Note 2: transport port is the port number of the SS (see RFC 3264 clause 6).

Note 3: The bandwidth-value is copied from step 2.

Note 4: Void.

Require

option-tag

precondition (shall be present if SDP message-body present)

Message-body

Header optional

Contents if present: The following SDP types and values shall be present.

Session description:

– v=0

– o=(username) (sess-id) (sess-version) IN (addrtype) (unicast-address for UE) [Note 2]

– s=(session name)

– c=IN (addrtype) (connection-address for UE) [Note 1]

– b=AS: (bandwidth-value)

Time description:

– t=0 0

Media description:

– m=audio (transport port) RTP/AVP (fmt) [Note 3]

– c=IN (addrtype) (connection-address for UE) [Note 1]

– b=AS: (bandwidth-value)

– b=RS: (bandwidth-value)

– b=RR: (bandwidth-value)

Attributes for media:

– a=rtpmap: (payload type) AMR/8000 [Note 3, 5]

– a=fmtp: (format) [Note 3, 4]

Attributes for preconditions:

– a=curr:qos local sendrecv

– a=curr:qos remote none

– a=des:qos mandatory local sendrecv

– a=des:qos optional remote sendrecv or a=des:qos mandatory remote sendrecv

Note 1: At least one "c=" field shall be present.

Note 2: "o=" line identical to previous SDP sent by UE except that sess-version is incremented by one.

Note 3: The value for fmt, payload type and format is not checked

Note 4: Parameters for the AMR codec are not checked

Note 5: The AMR channel number shall be “/1” or omitted.