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 7]

– b=RR: (bandwidth-value) [Note 7]

Attributes for media:

– a=rtpmap: (payload type) AMR/8000 [Note 8]

– a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 9]

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

– a=fmtp: (format)

– a=ecn-capable-rtp: leap ect=0 [Note 3]

– a=rtcp-fb:* nack ecn [Note 3]

– a=rtcp-xr:ecn-sum [Note 3]

– a=rtcp-rsize [Note 3]

– 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: Void.

Note 3: Attributes for ECN Capability may be present if the UE supports Explicit Congestion Notification.

Note 4: Void.

Note 5: Void

Note 6: Void

Note 7: The RR value must be greater than 0. The RS value can be any value.

Note 8: The AMR channel number shall be “/1” or omitted.

Note 9: Values from 0 to 220 are allowed

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, 4]

– b=AS:37

– b=RS: (bandwidth-value) [Note 5]

– b=RR: (bandwidth-value) [Note 5]

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=ecn-capable-rtp: leap ect=0 [Note 2]

– a=rtcp-fb:* nack ecn [Note 2]

– a=rtcp-xr:ecn-sum [Note 2]

– 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: Attributes for ECN Capability are present if the UE supports Explicit Congestion Notification.

Note 3: Void.

Note 4: transport port is the port number of the SS (see RFC 3264 clause 6).

Note 5: The bandwidth-value is copied from step 2.

Note 6: Void

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)

– 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 and other applicable codec are not checked

Content-Type

Header optional

Contents if present:

media-type

application/sdp

Content-Length

Contents if header Content-Type is present:

Value

length of message-body

Message-body

Header present if Prack (step 5) contained SDP.

Contents if present: SDP body of the 200 OK response copied from the received PRACK and modified as follows:

– IP address on "c=" lines and transport port on "m=" lines changed to indicate to which IP address and port the UE should start sending the media;

– "o=" line identical to previous SDP sent by SS except that sess-version is incremented.

Attributes for preconditions:

• a=curr:qos remote sendrecv

Message-body

Same contents as specified in step 5.

Content-Type

Header optional

Contents if present:

media-type

application/sdp

Content-Length

Contents if header Content-Type is present:

Value

length of message-body

Message-body

SDP body of the 200 response copied from the received UPDATE and modified as follows:

– IP address on "c=" lines and transport port on "m=" lines changed to indicate to which IP address and port the UE should start sending the media;

– “o=” line identical to previous SDP sent by SS except that sess-version is incremented.

Attributes for preconditions:

• a=curr:qos remote sendrecv