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# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
capability_types:
# https://en.wikipedia.org/wiki/IP_Multimedia_Subsystem#Core_network
ims.functions.Root:
derived_from: tosca.capabilities.Root
ims.functions.CTF: # not mentioned in Wikipedia
description: >-
Charging Trigger Function.
derived_from: ims.functions.Root
ims.functions.XDMS: # not mentioned in Wikipedia
description: >-
XML Document Management Server
derived_from: ims.functions.Root
ims.functions.HSS:
description: >-
The home subscriber server (HSS), or user profile server function (UPSF), is a master user
database that supports the IMS network entities that actually handle calls. It contains the
subscription-related information (subscriber profiles), performs authentication and
authorization of the user, and can provide information about the subscriber's location and IP
information. It is similar to the GSM home location register (HLR) and Authentication centre
(AuC).
A subscriber location function (SLF) is needed to map user addresses when multiple HSSs are
used.
derived_from: ims.functions.Root
ims.functions.CSCF:
description: >-
Several roles of SIP servers or proxies, collectively called Call Session Control Function
(CSCF), are used to process SIP signalling packets in the IMS.
derived_from: ims.functions.Root
ims.functions.P-CSCF:
description: >-
A Proxy-CSCF (P-CSCF) is a SIP proxy that is the first point of contact for the IMS terminal.
It can be located either in the visited network (in full IMS networks) or in the home network
(when the visited network is not IMS compliant yet). Some networks may use a Session Border
Controller (SBC) for this function. The P-CSCF is at its core a specialized SBC for the
User–network interface which not only protects the network, but also the IMS terminal. The use
of an additional SBC between the IMS terminal and the P-CSCF is unnecessary and infeasible due
to the signaling being encrypted on this leg. The terminal discovers its P-CSCF with either
DHCP, or it may be configured (e.g. during initial provisioning or via a 3GPP IMS Management
Object (MO)) or in the ISIM or assigned in the PDP Context (in General Packet Radio Service
(GPRS)).
derived_from: ims.functions.CSCF
ims.functions.I-CSCF:
description: >-
An Interrogating-CSCF (I-CSCF) is another SIP function located at the edge of an
administrative domain. Its IP address is published in the Domain Name System (DNS) of the
domain (using NAPTR and SRV type of DNS records), so that remote servers can find it, and use
it as a forwarding point (e.g., registering) for SIP packets to this domain.
derived_from: ims.functions.CSCF
ims.functions.S-CSCF:
description: >-
A Serving-CSCF (S-CSCF) is the central node of the signalling plane. It is a SIP server, but
performs session control too. It is always located in the home network. It uses Diameter Cx
and Dx interfaces to the HSS to download user profiles and upload user-to-S-CSCF associations
(the user profile is only cached locally for processing reasons only and is not changed). All
necessary subscriber profile information is loaded from the HSS.
derived_from: ims.functions.CSCF
ims.functions.AS:
description: >-
SIP Application servers (AS) host and execute services, and interface with the S-CSCF using
SIP. An example of an application server that is being developed in 3GPP is the Voice call
continuity Function (VCC Server). Depending on the actual service, the AS can operate in SIP
proxy mode, SIP UA (user agent) mode or SIP B2BUA mode. An AS can be located in the home
network or in an external third-party network. If located in the home network, it can query
the HSS with the Diameter Sh or Si interfaces (for a SIP-AS).
derived_from: ims.functions.Root
ims.functions.SIP-AS:
description: >-
Host and execute IMS specific services.
derived_from: ims.functions.AS
ims.functions.IM-SSF:
description: >-
IP Multimedia Service Switching Function. Interfaces SIP to CAP to communicate with CAMEL
Application Servers.
derived_from: ims.functions.AS
ims.functions.OSA-SCS:
description: >-
OSA service capability server. Interfaces SIP to the OSA framework.
derived_from: ims.functions.AS
ims.functions.AS-ILCM:
description: >-
The AS-ILCM (Application Server - Incoming Leg Control Model) stores transaction state, and
may optionally store session state depending on the specific service being executed. The
AS-ILCM interfaces to the S-CSCF (ILCM) for an incoming leg. Application Logic provides the
service(s) and interacts between the AS-ILCM and AS-OLCM.
derived_from: ims.functions.AS
ims.functions.AS-OLCM:
description: >-
The AS-OLCM (Application Server - Outgoing Leg Control Model) stores transaction state, and
may optionally store session state depending on the specific service being executed. The
AS-OLCM interfaces to the S-CSCF (OLCM) for an outgoing leg. Application Logic provides the
service(s) and interacts between the AS-ILCM and AS-OLCM.
derived_from: ims.functions.AS
ims.functions.MRF:
description: >-
The Media Resource Function (MRF) provides media related functions such as media manipulation
(e.g. voice stream mixing) and playing of tones and announcements.
Each MRF is further divided into a media resource function controller (MRFC) and a media
resource function processor (MRFP).
derived_from: ims.functions.Root
ims.functions.MRFC:
description: >-
The MRFC is a signalling plane node that interprets information coming from an AS and S-CSCF
to control the MRFP.
derived_from: ims.functions.Root
ims.functions.MRFP:
description: >-
The MRFP is a media plane node used to mix, source or process media streams. It can also
manage access right to shared resources.
derived_from: ims.functions.Root
ims.functions.MRB:
description: >-
The Media Resource Broker (MRB) is a functional entity that is responsible for both collection
of appropriate published MRF information and supplying of appropriate MRF information to
consuming entities such as the AS. MRB can be used in two modes:
* Query mode: AS queries the MRB for media and sets up the call using the response of MRB
* In-Line Mode: AS sends a SIP INVITE to the MRB. The MRB sets up the call
derived_from: ims.functions.Root
ims.functions.BGCF:
description: >-
A Breakout Gateway Control Function (BGCF) is a SIP proxy which processes requests for routing
from an S-CSCF when the S-CSCF has determined that the session cannot be routed using DNS or
ENUM/DNS. It includes routing functionality based on telephone numbers.
derived_from: ims.functions.Root
ims.functions.PTSNGateway:
description: >-
A PSTN/CS gateway interfaces with PSTN circuit switched (CS) networks. For signalling, CS
networks use ISDN User Part (ISUP) (or BICC) over Message Transfer Part (MTP), while IMS uses
SIP over IP. For media, CS networks use Pulse-code modulation (PCM), while IMS uses Real-time
Transport Protocol (RTP).
derived_from: ims.functions.Root
ims.functions.SGW:
description: >-
A signalling gateway (SGW) interfaces with the signalling plane of the CS. It transforms lower
layer protocols as Stream Control Transmission Protocol (SCTP, an IP protocol) into Message
Transfer Part (MTP, an Signalling System 7 (SS7) protocol), to pass ISDN User Part (ISUP) from
the MGCF to the CS network.
derived_from: ims.functions.PTSNGateway
ims.functions.MGCF:
description: >-
A media gateway controller function (MGCF) is a SIP endpoint that does call control protocol
conversion between SIP and ISUP/BICC and interfaces with the SGW over SCTP. It also controls
the resources in a Media Gateway (MGW) across an H.248 interface.
derived_from: ims.functions.PTSNGateway
ims.functions.MGW:
description: >-
A media gateway (MGW) interfaces with the media plane of the CS network, by converting between
RTP and PCM. It can also transcode when the codecs don't match (e.g., IMS might use AMR, PSTN
might use G.711).
derived_from: ims.functions.PTSNGateway
# https://en.wikipedia.org/wiki/IP_Multimedia_Subsystem#Interfaces_description
ims.interfaces.Diameter:
derived_from: tosca.capabilities.Endpoint
ims.interfaces.TCP:
derived_from: tosca.capabilities.Endpoint
ims.interfaces.SIP:
derived_from: tosca.capabilities.Endpoint
properties:
protocol: # override
type: string
default: sip
ims.interfaces.RTP:
derived_from: tosca.capabilities.Endpoint
properties:
protocol: # override
type: string
default: rtp
ims.interfaces.H248:
derived_from: tosca.capabilities.Endpoint
properties:
protocol: # override
type: string
default: h248
ims.interfaces.HTTP:
derived_from: tosca.capabilities.Endpoint
properties:
protocol: # override
type: string
default: http
ims.interfaces.MAP:
derived_from: tosca.capabilities.Endpoint
properties:
protocol: # override
type: string
default: map
ims.interfaces.Cr:
description: >-
Used by MRFC to fetch documents (e.g. scripts, announcement files, and other resources) from
an AS. Also used for media control related commands.
derived_from: ims.interfaces.TCP
ims.interfaces.Cx:
description: >-
Used to send subscriber data to the S-CSCF; including filter criteria and their priority. Also
used to furnish CDF and/or OCF addresses.
derived_from: ims.interfaces.Diameter
ims.interfaces.Dh:
description: >-
Used by AS to find the HSS holding the user profile information in a multi-HSS environment.
DH_SLF_QUERY indicates an IMPU and DX_SLF_RESP return the HSS name.
derived_from: ims.interfaces.Diameter
ims.interfaces.Dx:
description: >-
Used by I-CSCF or S-CSCF to find a correct HSS in a multi-HSS environment. DX_SLF_QUERY
indicates an IMPU and DX_SLF_RESP return the HSS name.
derived_from: ims.interfaces.Diameter
ims.interfaces.Gm:
description: >-
Used to exchange messages between SIP user equipment (UE) or Voip gateway and P-CSCF.
derived_from: ims.interfaces.SIP
ims.interfaces.Go:
description: >-
Allows operators to control QoS in a user plane and exchange charging correlation
information between IMS and GPRS network.
derived_from: ims.interfaces.Diameter
ims.interfaces.Gq:
description: >-
Used to exchange policy decisions-related information between P-CSCF and PDF.
derived_from: ims.interfaces.Diameter
ims.interfaces.Gx:
description: >-
Used to exchange policy decisions-related information between PCEF and PCRF.
derived_from: ims.interfaces.Diameter
ims.interfaces.Gy:
description: >-
Used for online flow-based bearer charging. Functionally equivalent to Ro interface.
derived_from: ims.interfaces.Diameter
ims.interfaces.ISC:
description: >-
Reference point between S-CSCF and AS. Main functions are to:
* Notify the AS of the registered IMPU, registration state and UE capabilities
* Supply the AS with information to allow it to execute multiple services
* Convey charging function addresses
derived_from: ims.interfaces.SIP
ims.interfaces.Ici:
description: >-
Used to exchange messages between an IBCF and another IBCF belonging to a different IMS
network.
derived_from: ims.interfaces.SIP
ims.interfaces.Izi:
description: >-
Used to forward media streams from a TrGW to another TrGW belonging to a different IMS
network.
derived_from: ims.interfaces.RTP
ims.interfaces.Ma:
description: >-
Main functions are to:
* Forward SIP requests which are destined to a public service identity hosted by the AS
* Originate a session on behalf of a user or public service identity, if the AS has no
knowledge of a S-CSCF assigned to that user or public service identity
* Convey charging function addresses
derived_from: ims.interfaces.SIP
ims.interfaces.Mg:
description: >-
ISUP signalling to SIP signalling and forwards SIP signalling to I-CSCF.
derived_from: ims.interfaces.SIP
ims.interfaces.Mi:
description: >-
Used to exchange messages between S-CSCF and BGCF.
derived_from: ims.interfaces.SIP
ims.interfaces.Mj:
description: >-
Used for the interworking with the PSTN/CS domain, when the BGCF has determined that a
breakout should occur in the same IMS network to send SIP message from BGCF to MGCF.
derived_from: ims.interfaces.SIP
ims.interfaces.Mk:
description: >-
Used for the interworking with the PSTN/CS domain, when the BGCF has determined that a
breakout should occur in another IMS network to send SIP message from BGCF to the BGCF in the
other network.
derived_from: ims.interfaces.SIP
ims.interfaces.Mm:
description: >-
Used for exchanging messages between IMS and external IP networks.
derived_from: ims.interfaces.SIP
ims.interfaces.Mn:
description: >-
Allows control of user-plane resources.
derived_from: ims.interfaces.H248
ims.interfaces.Mp:
description: >-
Allows an MRFC to control media stream resources provided by an MRFP.
derived_from: ims.interfaces.H248
ims.interfaces.Mr:
description: >-
Used to exchange information between S-CSCF and MRFC.
derived_from: ims.interfaces.SIP
ims.interfaces.Mr2:
description: >-
Used to exchange session controls between AS and MRFC.
derived_from: ims.interfaces.SIP
ims.interfaces.Mw:
description: >-
Used to exchange messages between CSCFs. AGCF appears as a P-CSCF to the other CSCFs.
derived_from: ims.interfaces.SIP
ims.interfaces.Mx:
description: >-
Used for the interworking with another IMS network, when the BGCF has determined that a
breakout should occur in the other IMS network to send SIP message from BGCF to the IBCF in
the other network.
derived_from: ims.interfaces.SIP
ims.interfaces.P1:
description: >-
Used for call control services by AGCF to control H.248 A-MGW and residential gateways.
derived_from: ims.interfaces.H248
ims.interfaces.P2:
description: >-
Reference point between AGCF and CSCF.
derived_from: ims.interfaces.SIP
ims.interfaces.Rc:
description: >-
Used by the AS to request that media resources be assigned to a call when using MRB in-line
mode or in query mode.
derived_from: ims.interfaces.SIP
ims.interfaces.Rf:
description: >-
Used to exchange offline charging information with CDF.
derived_from: ims.interfaces.Diameter
ims.interfaces.Ro:
description: >-
Used to exchange online charging information with OCF.
derived_from: ims.interfaces.Diameter
ims.interfaces.Rx:
description: >-
Used to exchange policy and charging related information between P-CSCF and PCRF. Replacement
for the Gq reference point.
derived_from: ims.interfaces.Diameter
ims.interfaces.Sh:
description: >-
Used to exchange User Profile information (e.g., user-related data, group lists,
user-service-related information or user location information or charging function addresses
(used when the AS has not received the third-party REGISTER for a user)) between an AS (SIP
AS or OSA SCS) and HSS. Also allow AS to activate/deactivate filter criteria stored in the HSS
on a per-subscriber basis.
derived_from: ims.interfaces.Diameter
ims.interfaces.Si:
description: >-
Transports CAMEL subscription information, including triggers for use by CAMEL-based
application services information.
derived_from: ims.interfaces.MAP
ims.interfaces.Sr:
description: >-
Used by MRFC to fetch documents (scripts and other resources) from an AS.
derived_from: ims.interfaces.HTTP
ims.interfaces.Ut:
description: >-
Facilitates the management of subscriber information related to services and settings.
derived_from: ims.interfaces.HTTP
ims.interfaces.Z:
description: >-
Conversion of POTS services to SIP messages.
derived_from: tosca.capabilities.Root
node_types:
ims.nodes.IMS:
derived_from: tosca.nodes.Root
capabilities:
p-cscf: ims.functions.P-CSCF
i-cscf: ims.functions.I-CSCF
s-cscf: ims.functions.S-CSCF
hss: ims.functions.HSS
ctf: ims.functions.CTF
xdms: ims.functions.XDMS
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