X.P0048-0
1
7
2
7.1
Short Message Service over IMS
SIP Related Procedures
Introduction
Void.
3
4
7.2
5
7.2.1
Functional entities
User Equipment (UE)
6
A UE may implement the roles of SMS-over-IMS sender (see section 7.3.1) and
7
SMS-over-IMS receiver (see section 7.3.2) for sending and receiving SMS over IMS.
8
The UE shall follow the procedures defined in [C.S0015] for sending and receiving
9
SMS over 1x CS.
10
7.2.2
An AS may implement the role of an SMS-GW (see section 7.3.3).
11
12
Application Server (AS)
7.2.3
Home Subscriber Server (HSS)
13
During the UE registration, if the subscriber has subscribed to SMS-over-IMS service,
14
the HSS shall include in the iFCs downloaded to the S-CSCF, the SPTs [MMD
15
Part-5] for routing relevant SIP messages to the SMS-GW. The SIP messages that are
16
routed to the SMS-GW include registration messages, originating SMS-over-IMS
17
messages, and terminating SMS-over-IMS messages. In addition to the SPTs, the
18
HSS shall include the MDN of the UE within the Service Information element (see
19
[MMD Part-5]) of the initial filter criteria. The MDN will be transparently passed by
20
the S-CSCF to the SMS-GW during third-party registration.
21
7.2.4
There are no SMS over IMS specific procedures at the HLR.
22
23
Home Location Register (HLR)
7.2.5
S-CSCF
24
When the S-CSCF sends a third-party SIP REGISTER to the SMS-GW, the S-CSCF
25
shall follow the procedures as specified in [MMD Part-4]. In addition, if the
26
“Timestamp: header is sent by the UE in a SIP REGISTER, the S-CSCF shall
27
transparently pass that along in the third-party SIP REGISTER to the SMS-GW (as it
28
would to all other AS in user's profile for the SIP REGISTER).
1
7.1 Introduction
1
7.3
2
7.3.1
3
7.3.1.1
Roles
SMS-over-IMS sender
General Procedures
4
In addition to the procedures specified in section 7.3.1, the SMS-over-IMS sender
5
shall support the appropriate UE related procedures specified in [MMD Part-4]. The
6
SMS-over-IMS sender shall support the procedures defined in [C.S0015] for
7
constructing an SMS message.
8
The SMS-over-IMS sender shall not submit simultaneous SMS-over-IMS messages
9
over IMS to the originating SMS-GW. The SMS-over-IMS sender shall wait for an
10
acknowledgement from the originating SMS-GW indicating that the previously
11
submitted SMS-over-IMS has been received, prior to submitting another
12
SMS-over-IMS message to the originating SMS-GW.
13
7.3.1.2
Registration
14
When the SMS-over-IMS sender registers with the IMS subsystem, the
15
SMS-over-IMS sender shall apply the procedures as specified in [MMD Part-4].
16
When constructing a SIP REGISTER, the SMS-over-IMS sender shall include a
17
Timestamp: header [RFC 3261] in the SIP REGISTER. The value of the Timestamp:
18
header shall be set to the time, in seconds since January 1, 1900 00:00 UTC, at which
19
the SMS-over-IMS sender generated the SIP REGISTER.
20
If the SMS-over-IMS sender is both IMS registered and 1x CS registered and the
21
SMS-over-IMS sender detects that the IMS network coverage is temporarily
22
unavailable but the SMS-over-IMS sender still has 1x CS network coverage, based
23
on operator policy, the SMS-over-IMS sender shall send an SMS on the 1x CS
24
network, to notify the SMS-GW that it is reachable only through the 1x CS domain.
25
The SMS message is constructed as specified in section 5.3.2.1 of [VCC] with the
26
following exception:

27
The SMS-over-IMS sender shall set the Parameter ID '00000100'
28
(Destination Address) of the SMS Point-to-Point message to the address of
29
the SMS-GW.
30
The SMS-over-IMS sender shall follow the procedures specified in section 5.3.2.2 of
31
[VCC] for processing SMS acknowledgements.
32
When the SMS-over-IMS sender regains IMS coverage, if the SMS-over-IMS sender
33
had previously sent an SMS with a 1x CS-only status indication, the SMS-over-IMS
34
sender shall send a SIP re-REGISTER over IMS to indicate to the SMS-GW that it
35
has regained IMS coverage.
7.3 Roles
2
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7.3.1.3
Short Message Service over IMS
Submitting a short message
2
When an SMS-over-IMS sender wants to submit an SMS message over IMS, the
3
SMS-over-IMS sender shall send a SIP MESSAGE with the following information:
The Request-URI shall be set to SIP URI or tel URI of the destination UE, or, if
4
available, the SIP URI of the SMS-GW.
5
6
the Request-Disposition: header shall contain the "no-fork" directive
7
the Content-Type: header shall be set to "application/vnd.3gpp2.sms"
8
The body of the request shall contain an "SMS Submit Message", including the
9
SMS Transport layer and SMS Teleservice layer information, as defined in
10
[C.S0015] and encoded in binary. The SMS-over-IMS sender shall set the value
11
of the Content-Transfer-Encoding: header to "binary".
the From: header shall contain the tel URI or SIP URI of the SMS-over-IMS
12
sender.
13
the To: header shall be set to the URI specified in the Request-URI.
14
15
If the SMS-over-IMS sender included the SMS Transport Layer parameter "Bearer
16
Reply Option" in the encapsulated SMS Point-to-Point message, the SMS-over-IMS
17
sender shall process the SMS Transport layer "SMS Acknowledge" message as
18
specified in section 7.3.1.4.
19
7.3.1.4
Processing an SMS Transport layer "SMS Acknowledge" message
20
Upon receiving a SIP MESSAGE with the Content-type: header set to
21
"application/vnd.3gpp2.sms", which contains an encapsulated "SMS Acknowledge"
22
message, the SMS-over-IMS sender shall:
23
a.
generate a SIP response according to [RFC 3428]; and
24
b.
extract the SMS message from the SIP MESSAGE body and process the "SMS
Acknowledge" message as defined in [C.S0015].
25
26
27
7.3.1.5
Processing of “SMS User Acknowledgement Message” or “SMS
Delivery Acknowledgement Message”
28
Upon
receiving
a
SIP
MESSAGE
with
a
body
of
MIME
type
29
“application/vnd.3gpp2.sms” containing an “SMS User Acknowledgement Message”
30
or “SMS Delivery Acknowledgement Message”, the SMS-over-IMS sender shall:
31
a.
generate a SIP response according to [RFC 3428];
3
7.3 Roles
b.
1
process the SMS Point-to-Point message received in the SIP MESSAGE as
defined in [C.S0015].
2
c.
3
if the SMS-GW had included the SMS Transport Layer parameter "Bearer Reply
4
Option" in the SMS message, the SMS-over-IMS sender shall generate the SMS
5
Transport layer "SMS Acknowledge" message as specified in section 7.3.2.4
6
with the exception that SMS-over-IMS sender, instead of the SMS-over-IMS
7
receiver, generates the "SMS Acknowledge" message.
8
Note: According to [C.S0015], if the incoming SMS message is an
9
"SMS Delivery Acknowledgement Message" or an "SMS User
10
Acknowledgement Message", the actions to be taken are
11
implementation dependent.
12
7.3.2
13
7.3.2.1
SMS-over-IMS receiver
General Procedures
14
In addition to the procedures specified in section 7.3.2, the SMS-over-IMS receiver
15
shall support the appropriate UE related procedures specified in [MMD Part-4]. The
16
SMS-over-IMS receiver shall support the procedures defined in [C.S0015] for
17
receiving an SMS message.
18
7.3.2.2
Registration
19
When the SMS-over-IMS receiver registers with the IMS subsystem, the
20
SMS-over-IMS receiver shall apply the procedures as specified in [MMD Part-4].
21
When constructing a SIP REGISTER, the SMS-over-IMS receiver shall include a
22
Timestamp: header [RFC 3261] in the SIP REGISTER. The value of the Timestamp:
23
header shall be set to the time, in seconds since January 1, 1900 00:00 UTC, at which
24
the SMS-over-IMS receiver generated the SIP REGISTER.
25
If the SMS-over-IMS receiver is both IMS registered and 1x CS registered and the
26
SMS-over-IMS receiver detects that the IMS network coverage is temporarily
27
unavailable but the SMS-over-IMS receiver still has 1x CS network coverage, based
28
on operator policy, the SMS-over-IMS receiver shall send an SMS on the 1x CS
29
network, to notify the SMS-GW that it is reachable only through the 1x CS domain. .
30
The SMS message is constructed as specified in section 5.3.2.1 of [VCC] with the
31
following exception:

32
the SMS-over-IMS receiver shall set the Parameter ID '00000100'
33
(Destination Address) of the SMS Point-to-Point message to the address of
34
the SMS-GW.
35
The SMS-over-IMS receiver shall follow the procedures specified in section 5.3.2.2
36
of [VCC] for processing SMS acknowledgements.
7.3 Roles
4
X.P0048-0
Short Message Service over IMS
1
When the SMS-over-IMS receiver regains IMS coverage, if the SMS-over-IMS
2
receiver had previously sent an SMS with a 1x CS-only status information, the
3
SMS-over-IMS receiver shall send a SIP re-REGISTER over IMS to indicate to the
4
SMS-GW that it has regained IMS coverage.
5
7.3.2.3
Receiving a short message
6
Upon receiving a SIP MESSAGE with the Content-type: header set to
7
"application/vnd.3gpp2.sms", which contains an "SMS Deliver Message", the
8
SMS-over-IMS receiver shall:
9
a.
generate a SIP response according to [RFC 3428].
10
b.
process the SMS Point-to-Point message received in the SIP MESSAGE as
defined in [C.S0015].
11
c.
12
if the SMS Transport Layer parameter "Bearer Reply Option" is included in the
13
SMS message, the SMS-over-IMS receiver shall save the SIP URI of the
14
SMS-GW and generate the SMS Transport layer "SMS Acknowledge" message
15
as specified in section 7.3.2.4.
16
7.3.2.4
SMS Acknowledge Message generation
17
When an SMS-over-IMS receiver wants to generate an SMS Transport layer "SMS
18
Acknowledge" message over IMS, the SMS-over-IMS receiver shall send a SIP
19
MESSAGE with the following information:
20
a.
21
NOTE: The address of the SMS-GW is obtained from the
22
P-Asserted-Identity: header of SMS-over-IMS message received in
23
section 7.3.2.3.
24
b.
the Request-Disposition: header shall contain the "no-fork" directive;
25
c.
the Content-Type: header shall contain "application/vnd.3gpp2.sms"; and
26
d.
the body of the request shall contain the SMS Transport layer "SMS
the Request-URI shall be set to the SIP URI of SMS-GW;
27
Acknowledge" message, constructed according to procedures defined in
28
[C.S0015] and encoded in binary format. The SMS-over-IMS receiver shall set
29
the value of the Content-Transfer-Encoding: header to "binary".
5
7.3 Roles
1
7.3.3
2
7.3.3.1
SMS-GW
General
3
An SMS-GW is an entity that stores and forwards SMS messages to and from an
4
SME that is either IMS registered and/or 1x CS registered.
5
In addition to the procedures specified in section 7.3.3, the SMS-GW shall support
6
the AS procedures specified in [MMD Part-4]. The SMS-GW shall support the
7
procedures defined in [C.S0015] for construction of an SMS message.
8
The SMS-GW shall not deliver simultaneous SMS-over-IMS messages to the
9
SMS-over-IMS receiver. The SMS-GW shall wait for an acknowledgement from the
10
SMS-over-IMS receiver indicating that the previously delivered SMS-over-IMS
11
message has been received, prior to delivering another SMS-over-IMS message to
12
the SMS-over-IMS receiver.
13
7.3.3.2
Processing of third-party registration/de-registration
14
Upon receiving a 3rd party SIP REGISTER from the S-CSCF and if the SMS-GW
15
supports the 3rd party registration/de-registration, the SMS-GW shall do the
16
following:
17

the SMS-GW shall send an appropriate SIP response (e.g., 200 OK) to the
SIP REGISTER.
18

19
the SMS-GW shall store the MDN sent in the message body of the SIP
20
REGISTER within the <service-info> XML element and the address of the
21
S-CSCF serving the UE extracted from the Contact: header of the SIP
22
REGISTER.

23
If the SMS-GW supports the IMSST feature and if a Timestamp: header is
24
present in the third-party SIP REGISTER, the SMS-GW shall store the
25
value of the header.

26
If the Expires: header contains a non-zero value, the SMS-GW shall mark
27
the UE as registered over IMS. If the Expires: header contains a zero value,
28
the SMS-GW shall mark the UE as unregistered over IMS. The SMS-GW
29
may optionally subscribe to the "reg" event package of the UE using the
30
public user identity received in the SIP REGISTER.
31
Upon receiving an SMS from the SMS-over-IMS sender or SMS-over-IMS receiver
32
with the Teleservice identifier set to IMSST and the SMS-GW supports the IMSST
33
feature, the SMS-GW shall do the following:

34
If the VCC Message Type is 'Domain-Attachment-Status' and the
35
'Domain-Status' field is set to 0x00 (1x CS-only), the SMS-GW shall check
36
to see whether the "Timestamp" field is later than the previously stored
37
timestamp value. If the time in the SMS message is later, the SMS-GW shall
7.3 Roles
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Short Message Service over IMS
1
store the new timestamp value, and shall mark the UE's status as reachable
2
only over 1x CS domain. Otherwise, the SMS-GW shall ignore the SMS
3
message.
4
7.3.3.3
5
Processing of SMS message submissions from SMS-over-IMS
sender
6
Upon receiving a SIP MESSAGE from an SMS-over-IMS sender with a body of
7
MIME type "application/vnd.3gpp2.sms" containing an "SMS Submit Message", the
8
originating SMS-GW shall:
9
a.
generate a SIP response according to [RFC 3428].
10
b.
process the SMS-Point-to-Point message received in SIP MESSAGE as defined
in [C.S0015].
11
c.
12
if the SMS-over-IMS sender had included the SMS Transport Layer parameter
13
"Bearer Reply Option" in the SMS message, the SMS-GW shall generate the
14
SMS Transport layer "SMS Acknowledge" message as specified in section
15
7.3.3.3.1.
d.
16
determine whether the SMS message needs to be forwarded to the destination
SMS-GW over IMS or MAP.
17
18
Note: It is outside the scope of this specification as to how the
19
SMS-GW determines whether SMS message needs to be forwarded
20
over MAP or IMS.

21
IMS, the SMS-GW shall follow the procedures defined in section 7.3.3.5
22

23
If the SMS message needs to be forwarded to the destination SMS-GW over
MAP, the SMS-GW shall follow the procedures defined in [MAP].
24
25
If the SMS message needs to be forwarded to the destination SMS-GW over
7.3.3.3.1
SMS Acknowledge Message generation
26
To generate an SMS Transport layer "SMS Acknowledge" message over IMS, the
27
originating SMS-GW shall send a SIP MESSAGE with the following information:
28
a.
29
NOTE: The URI of the SMS-over-IMS sender is obtained from the
30
P-Asserted-Identity of the SIP MESSAGE received in section
31
7.3.3.3.
32
b.
the Request-Disposition: header shall contain the "no-fork" directive.
33
c.
the Content-Type: header shall contain "application/vnd.3gpp2.sms"; and
the Request-URI shall be set to the SMS-over-IMS sender's SIP URI or tel URI.
7
7.3 Roles
d.
1
the body of the request shall contain the SMS Transport layer "SMS
2
Acknowledge" message, constructed according to procedures defined in
3
[C.S0015] and encoded in binary format. The SMS-GW shall set the value of the
4
Content-Transfer-Encoding: header to "binary".
5
7.3.3.3.2
Forwarding of delivery acknowledgement at the originating SMS-GW
6
Upon receiving an SMS message from a terminating SMS-GW over MAP or IMS
7
containing a "SMS Delivery Acknowledgement Message", the originating SMS-GW
8
shall forward the "SMS Delivery Acknowledgement Message" to the UE based on
9
the following procedures:
a.
10
if the preferred domain is IMS and the UE is registered over IMS, the SMS-GW
11
shall construct a SIP MESSAGE request with the following information:
12
1.
the Request-URI shall be set to the tel URI or SIP URI of the
SMS-over-IMS sender.
13
14
2.
the To: header shall be set to the same URI used in the Request-URI.
15
3.
the From: header shall contain the SIP URI of the SMS-GW.
16
4.
the P-Asserted-Identity: header shall contain the SIP URI of the SMS-GW.
17
5.
the Request-Disposition: header shall contain the "no-fork" directive.
18
6.
P-Charging-Vector: header shall contain the parameters populated as
specified in [MMD Part-4].
19
20
7.
the Content-Type: header shall contain "application/vnd.3gpp2.sms"; and
21
8.
the body of the request shall contain the “SMS Delivery Acknowledgement”
22
message received from the terminating SMS GW encoded in binary format.
23
The SMS-GW shall set the value of the Content-Transfer-Encoding: header
24
to “binary”.
25
and send the SIP MESSAGE request to the SMS-over-IMS sender as specified in
26
[MMD Part-4];
b.
27
if the preferred domain is 1x CS and the UE is registered in the 1x CS, the
28
SMS-GW shall following the procedures defined in [C.S0015] for delivering
29
SMS messages to the UE over 1x CS.
c.
30
if the UE is not registered in the preferred domain, based on operator policy, the
31
SMS-GW may try to deliver the SMS message over other non-preferred domains,
32
using the appropriate mechanisms and procedures specific to that domain.
7.3 Roles
8
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7.3.3.4
Short Message Service over IMS
Processing of SMS messages deliveries to SMS-over-IMS receiver
2
Upon receiving an SMS message from an originating SMS-GW over MAP or IMS,
3
the terminating SMS-GW shall do the following:
4
a.
process the contents of the SMS message as defined in [C.S0015]. If the SMS
5
message was received over IMS, the SMS-GW shall extract the SMS message
6
from the body of the SIP MESSAGE.
b.
7
determine whether it is responsible for SMS message deliveries to the destined
8
UE. If yes, proceed to step c. Otherwise, return an appropriate error response
9
back to the originating SMS-GW.
c.
10
determine the preferred domain over which the SMS needs to be delivered to the
11
UE:
12
1.
if the preferred domain is IMS and the UE is registered over IMS, the
13
SMS-GW shall follow the procedures defined in section 7.3.3.4.1 for
14
delivering SMS messages over IMS.
2.
15
if the preferred domain is 1x CS and the UE is registered in the 1x CS, the
16
SMS-GW shall follow the procedures defined in [MAP] for delivering SMS
17
messages to the UE over 1x CS.
3.
18
if the UE is not registered in the preferred domain, based on operator policy,
19
the SMS-GW may try to deliver the SMS message over other non-preferred
20
domains, using the appropriate mechanisms and procedures specific to that
21
domain.
22
7.3.3.4.1
Delivering SMS message to SMS-over-IMS receiver over IMS
23
When an SMS-GW wants to deliver an SMS message to an UE registered over IMS,
24
the SMS GW shall construct a SIP MESSAGE with the following information:
25
a.
the Request-URI shall be set to the tel URI or SIP URI of the UE to which the
message needs to be delivered.
26
27
b.
the Request-Disposition: header shall contain the "no-fork" directive.
28
c.
the Content-Type: header shall be set to "application/vnd.3gpp2.sms".
29
d.
the body of the request shall contain an "SMS Deliver Message", including the
30
SMS Transport layer and SMS Teleservice layer information, as defined in
31
[C.S0015] and encoded in binary. The SMS-over-IMS sender shall set the value
32
of the Content-Transfer-Encoding: header to "binary".
33
e.
the P-Asserted-Identity shall contain the SIP URI of the SMS-GW.
9
7.3 Roles
1
Upon receiving a SIP 2xx response from the UE, the SMS-GW shall do the
2
following:
3
a.
If the SMS-GW had included a "Bearer Reply Option" in the Transport layer of
4
the SMS message delivered to the UE, the SMS-GW shall wait for an "SMS
5
Acknowledge Message" from the UE before proceeding to step b. Otherwise,
6
proceeds to step c.
b.
7
Upon receiving a "SMS Acknowledge Message" from the UE, the SMS-GW
8
shall generate a SIP response according to [RFC 3428] and process the "SMS
9
Acknowledge message" according to [C.S0015].
c.
10
If the SMS message delivered to the UE contained a "Reply Option" with the
11
"DAK_REQ" field set to 1, the SMS GW shall generate an "SMS Delivery
12
Acknowledgment Message", as specified in [C.S0015], and send it towards the
13
originator of the SMS message using the procedures specified in [MAP] or the
14
procedures specified in section 7.3.3.5.4.1 over IMS.
15
7.3.3.5
16
7.3.3.5.1
SMS-GW to SMS-GW Communication
Terminating SMS-GW discovery procedure
17
Upon receiving an SMS message submitted by the SMS-over-IMS sender either over
18
the 1x CS or IMS domain , the originating SMS-GW will determine whether to
19
forward the SMS message to the terminating SMS-GW using the MAP or IMS.
20
If the originating SMS-GW decides to forward the submitted SMS message to a
21
terminating SMS-GW over IMS, it must either obtain the SIP URI of the
22
SMS-over-IMS receiver or discover the IP address of the terminating SMS-GW.
23
The originating SMS-GW obtains the SIP URI of the SMS-over-IMS receiver by
24
translating the E.164 number of the SMS-over-IMS receiver into a globally routable
25
SIP URI that resolves to the SMS-over-IMS receiver. This specification does not
26
mandate any particular mechanism for implementing the translation of the E.164
27
number into the SIP URI of the SMS-over-IMS receiver. The originating SMS-GW
28
may resolve the E.164 number into the SIP URI of the SMS-over-IMS receiver using
29
any available database or any public or private ENUM/DNS translation mechanism
30
(as specified in [RFC 3761]). Databases aspects of ENUM are outside the scope of
31
this document. However, once the originating SMS-GW acquires the SIP URI of the
32
SMS-over-IMS receiver, it will discover the entry point (I-CSCF) of the IMS
33
subsystem hosting the SMS-over-IMS receiver and follow the procedures specified in
34
[MMD Part-4] to route the SIP MESSAGE carrying the encapsulated SMS message.
35
Alternatively, the origination SMS-GW discovers the IP address of the terminating
36
SMS-GW by translating the E.164 number of the SMS-over-IMS receiver into a
37
globally routable SIP URI that resolves to the terminating SMS-GW. This
38
specification does not mandate any particular mechanism for implementing the
10
7.3 Roles
X.P0048-0
Short Message Service over IMS
1
translation of the E.164 number into the FQDN of the terminating SMS-GW. The
2
originating SMS-GW may resolve the E.164 number into the SIP URI of the
3
terminating SMS-GW using any available database or any public or private
4
ENUM/DNS translation mechanism (as specified in [RFC 3761]). Databases aspects
5
of ENUM are outside the scope of this document. However, once the originating
6
SMS-GW acquires the FQDN of the terminating SMS-GW, it will obtain the IP
7
address of the terminating SMS-GW by accessing the global DNS infrastructure.
8
Hence, the global DNS will be populated with the FQDN of the terminating
9
SMS-GW and the associated IP address (i.e. with AAAA and A resource records).
10
The originating SMS-GW shall send the SIP MESSAGE to terminating SMS-GW
11
according to the procedures defined in [RFC 3263].
12
If the originating SMS-GW decides to forward the submitted SMS message to a
13
terminating SMS-GW over MAP, or if the originating SMS-GW fails to discover the
14
terminating SMS-GW serving the SMS-over-IMS receiver over IMS, it shall deliver
15
the SMS message(s) to the terminating SMS-GW using the SMDPP procedures
16
defined in [MAP].
17
7.3.3.5.2
Routing the SIP MESSAGE to terminating SMS-GW over IMS
18
This section is applicable if the origination SMS-GW resolves the E.164 number of
19
the SMS-over-IMS receiver into the IP address of the terminating SMS-GW.
20
The document [MMD Part-2], section 5.4.12.3, specifies the IMS procedure for the
21
terminating AS hosting the subdomain PSI. In this document the SMS-GW assumes
22
the role of the AS and the SIP URI of the SMS-GW shall be the subdomain PSI.
23
There are two ways to route the SIP MESSAGEs that contains the submitted SMS
24
message from the originating SMS-GW to the terminating SMS-GW (i.e. the
25
terminating AS) over IMS. When the originating SMS-GW queries the global DNS
26
to resolve the FQDN of the terminating SMS-GW, it will obtain the IP address of
27
either:
28
a.
to the terminating SMS-GW; or
29
30
the terminating SMS-GW, in which case, the SIP MESSAGE is routed directly
b.
the entry point (i.e. the I-CSCF) of the IMS subsystem hosting the terminating
31
SMS-GW. In this case. The SIP MESSAGE is routed to the I-CSCF. The
32
I-CSCF recognizes the FQDN of the terminating SMS-GW as specified in the
33
Request-URI and consequently does not query the HSS to obtain the address of
34
the S-CSCF serving the target SMS-over-IMS receiver. The I-CSCF resolves the
35
FQDN to the address of the terminating SMS-GW (i.e. the destination AS
36
hosting the PSI) using an internal database (e.g. private DNS), and forwards the
37
requests directly to the terminating SMS-GW bypassing the S-CSCF.
11
7.3 Roles
1
The IMS network operator hosting the terminating SMS-GW selects which method it
2
will be use by populating the global DNS either as specified in step a or b. If b is
3
selected IMS network operator has to ensure that the I-CSCF has access to an internal
4
database (e.g. private DNS) that is configured with the IP address of the terminating
5
SMS-GW.
6
7.3.3.5.3
Procedures at the originating SMS-GW
7
When the originating SMS-GW decides to forward the received submit SMS
8
message to the terminating SMS-GW serving the SMS receiver over the IMS, the
9
originating SMS-GW shall:
1.
10
discover the IP address of terminating SMS-GW or the SIP URI of the
SMS-over-IMS receiver as described in section 7.3.3.5.1;
11
12
2.
construct a SIP MESSAGE with the following information:
13

Request-URI shall be set to the SIP URI of the terminating SMS-GW or the
14
SIP URI of the SMS-over-IMS receiver, which is obtained by resolving the
15
E.164 number of the SMS-over-IMS receiver as specified in section
16
7.3.3.5.1;
17

To: header shall contain the same URI used in the Request-URI;
18

From: header shall contain the tel URI or SIP URI of the SMS-over-IMS
sender;
19

20
P-Asserted-Identity: header shall contain the SIP URI of the originating
SMS-GW;
21

22
P-Charging-Vector: header shall contain the parameters populated as
specified in [MMD Part-4];
23
24
NOTE: The orig-ioi identifies the network operator from which the
25
SIP MESSAGE was sent;
26

Request-Disposition: header shall contain the "no-fork" directive;
27

Content-Type: header shall be set to "application/vnd.3gpp2.sms"; and
28

The body of the request shall contain an "SMS Submit Message", including
29
the SMS Transport layer and SMS Teleservice layer information, as defined
30
in [C.S0015] and encoded in binary. The SMS-GW shall also set the value
31
of the Content-Transfer-Encoding: header to "binary"; and
3.
32
forward the SIP MESSAGE to the terminating SMS-GW as specified in
section 7.3.3.5.1.
33
34
If the SIP MESSAGE sent by the originating SMS-GW to the terminating SMS-GW
35
included the submit SMS message with a “Reply Option” with the “DAK_REQ” set
36
to 1 as specified in [C.S0015], the originating SMS-GW will subsequently receive
7.3 Roles
12
X.P0048-0
Short Message Service over IMS
1
from the terminating SMS-GW a SIP MESSAGE that contains the SMS delivery
2
acknowledgement as specified in [C.S0015].
3
When the originating SMS-GW receives a SIP MESSAGE that contains the "SMS
4
Delivery Acknowledgment Message" as specified in [C.S0015], the originating
5
SMS-GW shall:
1.
6
3428];
7
2.
8
extract the SMS delivery acknowledgement from the payload of the
received SIP MESSAGE;
9
3.
10
forward the SMS delivery acknowledgement to the SMS-over-IMS sender
as described in section 7.3.3.3.2.
11
12
send a SIP 202 Accepted to the terminating SMS-GW according to [RFC
7.3.3.5.4
Procedures at the terminating SMS-GW
13
Upon receiving the SIP MESSAGE that contains a submit SMS message from the
14
originating SMS-GW over IMS, the terminating SMS-GW that serves the SMS
15
receiver shall:
16
1.
send a SIP 202 Accepted to the originating SMS-GW according to [RFC
3428];
17
18
2.
process the SMS Point-to-Point message received in SIP MESSAGE;
19
3.
save the SIP URI of the originating SMS-GW, contained in the
20
P-Asserted-Identity: header of the received SIP MESSAGE, and bind it to
21
the tel URI of the SMS-over-IMS sender; and
22
NOTE: The terminating SMS-GW will use the SIP URI of the
23
originating
24
acknowledgement to the originating SMS-GW.
25
4.
SMS-GW
when
sending
the
SMS
delivery
if the received SMS message included a "Bearer Reply Option" in the
26
Transport layer of the SMS message, send a "SMS Acknowledge message"
27
as described in section 7.3.3.5.4.1.
28
5.
over the IMS or 1x CS as described in section 7.3.1.4.
29
30
deliver the submitted SMS message to the SMS-over-IMS receiver either
6.
if the SMS message contained a "Reply Option" with the "DAK_REQ" field
31
set to 1, send a "Delivery Acknowledgement message" as described in
32
section 7.3.3.5.4.1.
13
7.3 Roles
1
7.3.3.5.4.1
Procedures at terminating SMS-GW for sending SMS Acknowledge or
2
SMS Delivery Acknowledgement over IMS.
3
When the terminating SMS-GW needs to send a "SMS Acknowledge message" or
4
"SMS Delivery Acknowledgement message" to the originating SMS-GW over IMS,
5
the terminating SMS-GW shall do the following:
6
1.
construct a SIP MESSAGE with the following information:
7

Request-URI shall be set to the SIP URI of the originating SMS-GW that
8
was saved and bound to the tel URI of the SMS-over-IMS sender (as
9
indicated above);
10

To: header shall contain the same URI used in the Request-URI;
11

From: header shall contain the tel URI or SIP URI of the SMS-over-IMS
receiver;
12

13
P-Asserted-Identity: header shall contain the SIP URI of the terminating
SMS-GW;
14

15
P-Charging-Vector: header shall contain the parameters populated as
specified in [MMD Part-4];
16
17
NOTE: The orig-ioi identifies the network operator from which the
18
SIP MESSAGE was sent.
19

Request-Disposition: header shall contain the "no-fork" directive;
20

Content-Type: header shall be set to "application/vnd.3gpp2.sms"; and
21

the body of the request shall contain the SMS Transport layer "SMS
22
Acknowledge message" or "SMS Delivery Acknowledgement message", as
23
appropriate, constructed according to procedures defined in [C.S0015] and
24
encoded in binary format. The SMS-GW shall also set the value of the
25
Content-Transfer-Encoding: header to "binary"; and
2.
26
resolve the saved the SIP URI of the originating SMS-GW saved from step
3 in section 7.3.3.5.4;
27
3.
28
forward the SIP MESSAGE to the IP address and port number of the
originating SMS-GW as specified in section 7.3.3.5.1.
29
30
7.3 Roles
14