ETSI TR 182 031 V3.1.1 (2010-09)

Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Remote CPN QoS Control; Study on CPN - RACS Interaction

DTR/TISPAN-02078-NGN-R3

General Information

• Status: Published
• Publication Date: 06-Sep-2010
• Technical Committee: TISPAN 2 - TISPAN Architecture
• Current Stage: 12 - Completion
• Due Date: 15-Sep-2010
• Completion Date: 07-Sep-2010

Standards Content (Sample)

Technical Report
Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
Remote CPN QoS Control;
Study on CPN - RACS Interaction

2 ETSI TR 182 031 V3.1.1 (2010-09)

Reference
DTR/TISPAN-02078-NGN-R3
Keywords
architecture, QoS
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3 ETSI TR 182 031 V3.1.1 (2010-09)
Contents
Intellectual Property Rights . 4
Foreword . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Abbreviations . 6
4 Use case analysis . 7
4.1 Reference scenarios and use cases . 7
4.1.1 Reference scenarios . 8
4.1.1.1 Access configuration scenarios . 8
4.1.1.2 NGN connection scenarios . 9
4.1.2 Use cases . 10
4.1.2.1 Access Line Resource and Admission control . 10
4.1.2.2 Access Line Policy Installation . 10
4.1.2.3 CPN Resource and Admission control . 10
4.1.2.4 CPN Policy Installation . 11
5 Functional Requirements for RACS-CPN Interaction . 11
5.1 Access Line Policy Installation . 11
5.1.1 Procedures. 11
5.1.2 Elementary Functions . 12
5.1.3 Policy Installation . 12
5.1.4 Informational Elements . 12
5.2 CPN and Access Line Resource and Admission Control . 14
5.2.1 Procedures. 14
5.2.2 Elementary Functions . 15
5.2.3 Admission Control . 17
5.2.4 Policy Installation . 17
5.2.5 NA(P)T Traversal Assistance . 17
5.2.6 Informational Elements . 17
6 Use case mapping to the TISPAN NGN architecture . 19
6.1 Access Line Policy Installation . 20
6.2 CPN and Access Line Resource and Admission Control . 22
7 Interworking with intra-CPN QoS control mechanisms . 23
8 Security and user privacy . 24
9 Signalling functions and protocols . 24
9.1 Direct connection . 24
9.2 Indirect connection . 25
10 Evaluation and recommendations for future work . 25
Annex A: Comparable work in other standardization bodies . 26
A.1 ITU-T . 26
Annex B: Implementation examples . 27
B.1 H(e)NB Implementation Scenario . 27
B.2 Untrusted non-3GPP access to 3GPP core network implementation Scenarios . 28
History . 31

ETSI
4 ETSI TR 182 031 V3.1.1 (2010-09)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Telecommunications and Internet
converged Services and Protocols for Advanced Networking (TISPAN).
ETSI
5 ETSI TR 182 031 V3.1.1 (2010-09)
1 Scope
The present document covers a use case analysis for the interaction of the TISPAN Resource and Admission Control
Sub-System (RACS) with the Customer Premises Network (CPN), as well as an analysis of required functional entities,
reference points and information flows. Furthermore, requirements for interworking with in-home QoS control
mechanisms are studied. The study concludes with a recommendation on the way, or ways, how RACS and CPN should
interact and interface, i.e. on one or several interworking architecture(s) proposal(s), taking into account security and
privacy aspects.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI ES 282 001: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Functional Architecture".
[i.2] ETSI ES 282 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Resource and Admission Control Sub-System (RACS):
Functional Architecture".
[i.3] ETSI ES 282 004: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN Functional Architecture; Network Attachment
Sub-System (NASS)".
[i.4] ETSI TS 185 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Customer Network Gateway (CNG) Architecture and
Reference Points".
[i.5] Broadband Forum TR-069 CPE WAN Management Protocol v1.1, Issue 1 Amendment 2,
December 2007.
[i.6] ETSI TS 124 229: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; IP multimedia call control protocol based on Session
Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 (3GPP TS 24.229)".
[i.7] ETSI TS 133 203: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; 3G security; Access security for IP-based services
(3GPP TS 33.203)".
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6 ETSI TR 182 031 V3.1.1 (2010-09)
[i.8] ETSI TS 183 048: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Resource and Admission Control System (RACS); Protocol
Signalling flows specification; RACS Stage 3".
[i.9] ETSI TS 122 220: "Universal Mobile Telecommunications System (UMTS); Service requirements
for Home Node B (HNB) and Home eNode B (HeNB) (3GPP TS 22.220)".
[i.10] 3GPP TR 23.830: "3rd Generation Partnership Project; Technical Specification Group Services
and System Aspects; Architecture aspects of Home NodeB and Home eNodeB".
[i.11] ETSI TS 125 467: "Universal Mobile Telecommunications System (UMTS); UTRAN architecture
for 3G Home Node B (HNB); Stage 2 (3GPP TS 25.467)".
[i.12] ETSI TS 187 001: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); NGN SECurity (SEC); Requirements".
[i.13] ETSI TS 181 005: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Service and Capability Requirements".
[i.14] ETSI TS 123 402: "Universal Mobile Telecommunications System (UMTS); LTE; Architecture
enhancements for non-3GPP accesses (3GPP TS 23.402)".
3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACP Admission Control Process
AF Application Function
ALG Application Layer Gateway
ALP Access Line Policy Installation
ALR Access Line Resource and Admission control
A-RACF Access-Resource and Admission Control Function
ASP Application Service Provider
AVP Attribute-Value Pair
BGF Border Gateway Function
CCI Charging Correlation Information
CND Customer Network Device
CNG Customer Network Gateway
CNG-ACF CNG-Admission Control Function
CNG-PCF CNG-Policy Control Function
CPE Customer Premise Equipment
CPI CPN Policy Installation
CPN Customer Premises Network
CRA CPN Resource and Admission control
C-RACF Core-Resource and Admission Control Function
CSCF Call Session Control Function
DITP Derivation and Installation of Traffic Policies
DSL Digital Subscriber Line
DSL Digital Subscriber Line
DSLAM Digital Subscriber Line Access Multiplexer
e4 reference point e4
ePDG evolved Packet Data Gateway
EUTRAN Evolved UMTS Terrestrial Radio Access Network
FE Functional Entity
FTTH Fibre To The Home
GC Gate Control
Gq' reference point Gq'
HMRP Handling of Media Request Priority
H-RAC Home Resource and Admission Control entity
HSRP Handling of Service Request Priority
Ia reference point Ia
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7 ETSI TR 182 031 V3.1.1 (2010-09)
IMS IP Multimedia Sub-System
IP Internet Protocol
IPMC IP Packet Marking Control
MITP Modification and Installation of new Traffic Policies
MLD Multicast Listener Discovery
MSAN Multi Services Access Node
NA(P)T Network Address and optional Port Translation
NASS Network Attachment Sub-System
NAT Network Address Translation
NBR NAT Binding Report
NE Network Element
NGN Next Generation Network
PCRF Policy and Charging Rule Function
P-CSCF Proxy-CSCF
PDN Packet Data Network
PON Passive Optical Fibre
QMTD QoS and Priority Mapping - Technology Dependent
QMTI QoS and Priority Mapping - Technology Independent
QoS Quality of Service
RACS Resource and Admission Control Sub-System
RCEF Resource Control Enforcement Function
Rd' Reference point Rd'
Re Reference point Re
Rf Reference point Rf
Ri' Reference point Ri'
RLC Rate Limiting Control
Rq Reference point Rq
Rr reference point Rr
RRP Reservation of Resources Process
SDP Session Description Protocol
SIP Session Initiation Protocol
SPDF Service-based Policy Decision Function
TCP Transmission Control Protocol
TDDP Technology Dependent Decision Point
TISPAN Telecommunications and Internet converged Services and Protocols for Advanced Networking
UDP User Datagram Protocol
UE User Equipment
VDSL Very high bit-rate Digital Subscriber Line
VGCF Voice Gateway Control Functions
x-RACF Generic Resource and Admission Control Function
4 Use case analysis
This clause details reference scenarios where the described CPN-RACS interaction is applicable and use cases from the
viewpoint of the RACS. The reference scenarios are studied regarding access network configuration options and ways
to connect end devices in the CPN to the NGN. The derived use cases from the view of the RACS can be split into
resource and admission control and policy installation processes, applicable on access lines and inside CPNs.
4.1 Reference scenarios and use cases
In the TISPAN NGN functional architecture described in ES 282 001 [i.1], a User Equipment (UE) attaches directly to
the NGN. TS 185 003 [i.4] defines an enhanced architecture where a Customer Network Gateway (CNG) can act either
as a UE in case it has e.g. an embedded SIP client or where Customer Network Devices (CNDs) with embedded clients
connect through a CNG to the NGN. In the latter case, depending on the use of signalling proxies in the CNG and
whether the CNG works in routed or bridged mode, the reference points to the NGN are either local ones inside the
Customer Premises Network (CPN) as defined in TS 185 003 [i.4] or the same ones as described in ES 282 001 [i.1].
Figure 1 depicts this architecture.
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8 ETSI TR 182 031 V3.1.1 (2010-09)
CND
CNG
CPN NGN
CND
Figure 1: Baseline architecture for NGN access including a CPN
This study makes the following basic assumptions:
1) A single CNG exists in the CPN as central gateway towards the NGN.
2) The CNG is reachable from the NGN on IP layer, e.g. for remote management purposes.
3) The CNG operates in routed mode.
4.1.1 Reference scenarios
This clause details reference scenarios for access configuration scenarios and for connection scenarios towards the NGN
on a NGN reference point level.
4.1.1.1 Access configuration scenarios
The CNG connects to an access node on the NGN side as described in ES 282 001 [i.1]. The following two scenarios
cover current fixed line broadband access technologies.
CNG
Access Node
CNG
CNG
CNG
Access Node
CNG
CNG
Figure 2: Configuration scenarios in access segment
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9 ETSI TR 182 031 V3.1.1 (2010-09)
The different options as shown in figure 2 are:
1) Each CNG has a dedicated, non-shared access line on its own. This is the case for e.g. xDSL access or FTTH
access with dedicated fibres.
2) A number of CNGs from different customers share a common access line segment. This scenario covers
e.g. shared PON access.
NOTE: In case PON is used to feed access nodes, option 1) applies. Each CNG has its dedicated access line.
4.1.1.2 NGN connection scenarios
For signalling and multimedia flows, three relevant options to connect to the NGN are possible according to
TS 185 003 [i.4]. The three reference scenarios are shown in figure 3 with the corresponding reference points
for signalling in the case of SIP signalling.
CND3
CND IMS
Z
SIP UA
RACS
VGCF
Gm
Gm NASS
CND2
IMS
Proxy/ B2BUA
Gm‘ Gm
CND SIP UA
CNG
CPN
NGN
CND1
Figure 3: Connection scenarios for CNDs (reference points for signalling shown)
The different options are:
1) The CNG itself is endpoint of signalling and media traffic. Reference points used are Gm for signalling with
the IMS and Dj for all traffic including media. An example use case is when an analogue phone connects to
the CNG. The CNG's VGCF acts as signalling and media endpoint on behalf of the CND (see CND3 in
figure 3). Similar functions for other types of media would be possible but are not yet standardized in ETSI
TISPAN.
2) The CNG is transparent to signalling and media traffic on a CND except for NA(P)T. Reference points in the
case of SIP signalling are then the same as above: Gm and Dj (see CND2 in figure 3, only signalling reference
points shown).
3) The CNG contains a signalling and/or media proxy as e.g. the Proxy B2BUA for the SIP signalling case and
the CNDs traffic traverses this entity. Used reference points are then Gm' and Dj'. (See CND1 in figure 3, only
signalling reference points shown.)
NOTE 1: Signalling over the Gm reference point may be encrypted, e.g. where IMS AKA as specified in
TS 133 203 [i.7] and TS 124 229 [i.6] is used.
NOTE 2: The Home(e)NodeB example is described in annex B.
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10 ETSI TR 182 031 V3.1.1 (2010-09)
4.1.2 Use cases
This clause details the investigated use cases from the viewpoint of the RACS.
The deployment of guaranteed QoS requires mainly two steps in the control plane. An Admission Control Process
(ACP) and a process for Modification and Installation of new Traffic Policies (MITP) as defined in
ES 282 003 [i.2]. Dynamic admission control is vital to allow for resource sharing in access and customer premises
networks without having to assign resources statically to specific devices or applications. The latter would disallow
re-using such resources by other devices or applications in case the assigned device or application is idle. Policy control
allows the installation and modification of rules on devices or applications e.g. to mark packets according to
classification rules on egress interfaces or to police traffic on ingress interfaces. It also enables to dynamically allow or
disallow specific traffic flows (Gate Control, GC). Whether there is a need for dynamic policy control depends thus on
deployment scenarios and on the level of trust between network elements or applications.
NOTE: This study covers use cases for the traffic types defined in ETSI TISPAN, i.e. uni- or bidirectional
unicast, and multicast originated from the NGN.
The use cases can be split into independent use cases that are valid for the access line and use cases that are valid for the
CPN. Still, both can be combined.
4.1.2.1 Access Line Resource and Admission control
Admission control on the access line can be performed in current TISPAN definitions by two methods.
1) An A-RACF performs admission control as described in ES 282 003 [i.2]. This requires RACS to be aware of
all sessions that require QoS. This also requires the RACS to be able to control the access node.
2) The CNG-ACF performs admission control as described in TS 185 003 [i.4]. This requires that either
signalling originates in the VGCF or that signalling traffic is readable for the CNG's application layer gateway
functions implemented in the Proxy B2BUA. The Proxy B2BUA has to then support all signalling protocols
used. This method will not be sufficient in case of a shared access medium.
In a use case where the RACS is not aware of the resources on the access node (e.g. it controls the MSAN but not the
DSLAMs in the case of GPON-fed VDSL), the admission control process can only be performed by the CNG.
Since the CNG can only be aware of the sessions that originate in itself or are unencrypted and detected by local ALGs,
the RACS can solve this problem by interconnecting directly or indirectly to the CNG-ACF (Admission Control
Function, see TS 185 003 [i.4]) and asking for resource reservation. Thus the following use case is determined:
• UC-ALR-1: The RACS interconnects with the CNG to request resource reservations on the access line.
4.1.2.2 Access Line Policy Installation
Dynamic policy installation and modification on the CNG is required to allow the CNG to dynamically prioritize,
allow or block outgoing traffic towards the access line.
Policy installation can be provided by the CNG-PCF (Policy Control Function, see TS 185 003 [i.4]). Since this
function requires an ALG in the CNG and cannot detect encrypted signalling, this approach is limited.
As an alternative, static (i.e. non-session-based) policies can be provisioned on the CNG e.g. by using the TR-69
Management Framework from the Broadband Forum [i.5]. Using static policies comes with the drawback that it is not
as granular as required for the media flows that are negotiated in real-time.
For dynamic policy installation on the CPN's side of the access line, the following use case results from this analysis:
• UC-ALP-1: The RACS interconnects with the CNG to request policy installation in the CNG's uplink
interface towards the NGN.
4.1.2.3 CPN Resource and Admission control
In case a CND connects to the CNG through a CPN, the traffic from the CND competes with traffic from other CNDs
as shown in figure 3 where CNDs 1 and 2 may compete for resources inside the CPN.
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11 ETSI TR 182 031 V3.1.1 (2010-09)
Thus, an admission control process inside the CPN is required. Using ALGs comes again with the above described
shortcomings. Two possible approaches can be thought of in the scope of RACS-CPN interaction:
• UC-CRA-1: The RACS requests resources from the CNG and the CNG itself reserves resources inside the
CPN as a completely separate process.
• UC-CRA-2: The RACS interconnects to all network elements inside the CPN for the purpose of resource and
admission control.
UC-CRA-2 is not further considered within the scope of the present document due to privacy and security
reasons. Furthermore - although in principle technically feasible - scalability problems are expected due to the
growing amount of in-home devices.
4.1.2.4 CPN Policy Installation
Dynamic policy installation inside the CPN may be required. Two possible approaches can be thought of in the scope of
RACS-CPN interaction:
• UC-CPI-1: A new FE in the CNG requests for policy installation inside the CPN based on a previous resource
and admission control procedure triggered by the RACS.
• UC-CPI-2: The RACS interconnects to all network elements inside the CPN for the purpose of policy
installation.
UC-CPI-2 is not further considered within the scope of the present document due to privacy and security
reasons. Furthermore - although in principle technically feasible - scalability problems are expected due to the
growing amount of in-home devices.
5 Functional Requirements for RACS-CPN Interaction
This clause describes the functional requirements for the interaction of RACS with the CPN for the use cases
UC-ALP-1, UC-CRA-1 and UC-ALR-1. For all use cases, the RACS needs to interconnect to a functional entity inside
the CPN which is named in this clause H-RAC and further de-composed in the next clauses of this study. Since the
CNG is the central gateway towards the NGN and the only device where reachability from the NGN side is given, the
H-RAC is embedded in the CNG. Clause 6 further specifies this function.
H-RAC RACS
CPN
Access line
CNG
NGN
Figure 4: RACS interconnection to the CNG (generic view)
5.1 Access Line Policy Installation
For use case UC-ALP-1, RACS performs resource and admission control on the access line and requests policy
installation from the CNG for traffic prioritization on its interface towards the NGN.
5.1.1 Procedures
The RACS requests policy installation for a set of flows by sending a policy installation request towards the H-RAC.
The H-RAC replies to this request as depicted in figure 5.
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12 ETSI TR 182 031 V3.1.1 (2010-09)
H-RAC RACS
(1) Locate CNG
(2) Policy Installation Request
(3) Enforcement
Control
(4) Policy Installation Reply
Figure 5: RACS interconnection to the CNG (generic view)
The required steps are as follows:
1) The RACS determines based on local policies whether a CNG is to be queried and then locates the CNG.
2) The RACS requests local policy installation.
3) The H-RAC enforces the appropriate policies on the access line.
4) The H-RAC confirms the resource availability to the RACS.
5.1.2 Elementary Functions
The required elementary function for the RACS beyond those defined in [i.2] are:
1) Determine based on local policies if the CNG needs to be contacted.
2) Locate the CNG and its H-RAC functional entity.
In this scenario, for each multimedia session the H-RAC needs to implement the installation, modification and removal
of policies, similar to an RCEF as described in [i.2], clause 6.3.7.1.1.1. The required elementary functions are:
1) Installation of Policies.
2) Gating.
3) Packet Marking.
4) Traffic Policing.
5) Removal of Policies.
6) Revoke of policies indication.
This enables the CNG to support the prioritization of media flows in both directions with appropriate QoS on the access
line interface. Details of the elementary functions are to be found in [i.2].
5.1.3 Policy Installation
Upon receiving the request for policy installation, the H-RAC installs the appropriate policies on the CNG.
5.1.4 Informational Elements
The required informational elements for the H-RAC in the access line policy installation case are a subset of those of
the Re reference point between x-RACF and RCEF as defined in clause 6.3.7 of ES 282 003 [i.2]. While the Function of
the x-RACF is restricted to an A-RACF, the function of the H-RAC in the use case here is the one of an RCEF. Table 1
lists the required informational elements.
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13 ETSI TR 182 031 V3.1.1 (2010-09)
Table 1: Policy Enforcement Install Request - Information Elements
Policy Enforcement Install Request (A-RACF -> H-RAC)
Request Originating Function Identifier Globally unique Identifier for the Request Originating
Function instance.
Resource Reservation Session ID The reference is a unique resource reservation session
identifier in the scope of the Request Originating Function
Identifier.
Policy Rule Installation (see note 1) The Policy Rule description, which is used to activate and
install a new Policy Rule as instructed from the A-RACF to
the H-RAC.
Policy Rule Definition (see note 2) The Policy Rule definition.
Policy Rule ID The identifier of a new Policy Rule to be activated at the
H-RAC.
Direction (see note 3) Direction of the flow.
Flow Id Identifier for the specific flow.
Flow control (see note 3) Enables or disables the opening of a gate to a particular flow.
IP Addresses (see note 3) Source and Destination IP addresses and Address Realm
that each address belongs to (see note 4).
Ports (see note 3) Source and Destination Port Numbers (see note 5).
Protocol (see note 3) Protocol Id.
Bandwidth (optional, see note 3) The maximum request bit rate.
Reservation Class (optional, see A particular index that identifies a set of traffic characteristics
note 3) of the flow (e.g. burstiness and packet size).
Transport Service Class (optional, Identifies the forwarding behaviour to be applied to the
see note 3) particular flow (see note 6).
Precedence Indicates the precedence that a Policy Rule should take
when related to others.
Report Type Indicates the type of reporting that the H-RAC is supposed to
provide to the A-RACF.
Policy Rule ID The identifier of a pre-defined Policy Rule to be activated at
the H-RAC.
Policy Rule Group ID (optional) The identifier of a set of pre-defined Policy Rules to be
activated at the H-RAC.
Traffic Class ID (optional) The identifier of a traffic class to be associated with a policy
rule.
NOTE 1: There needs to be at least one Information Element of this type present in the message.
NOTE 2: If Policy Rules for each direction need to be specified, several Policy Rule definitions have to be
included.
NOTE 3: These Information Elements describe the flow. Zero, one or several of them may be included in
the Policy Rule definition, in order to associate a given Policy Rule with IP Flows.
NOTE 4: An IP address prefix is supported.
NOTE 5: Port ranges are supported and can be defined by specifying the minimum and maximum value
or by using a wildcard.
NOTE 6: Transport Service Class is also part of the QoS profile provided by NASS (see ES 282 004
[i.3]).
The informational elements from the x-RACF - RCEF interconnection, which allow an RCEF to identify a (virtual)
subscriber port that the IP flow(s) traverse, are not required for access line policy installation on the CPN side. Thus, the
elements Subscriber-ID, Physical Access ID and Logical Access ID are not required.
NOTE: In the case of NA(P)T in the CNG, the standard procedure in TISPAN RACS is to include the CPN-local
address and the globally reachable address of the BGF in the flow description (see [i.8]). This allows the
CNG to identify flows and is sufficient even in the situation prior to creation of a NA(P)T binding . The
CNG can create a NA(P)T binding upon installation of the policy, before having received a first packet
matching the flow description from the CND.
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14 ETSI TR 182 031 V3.1.1 (2010-09)
The policy installation response contains the following informational elements:
Table 2: Policy Enforcement Installation/Modification Confirmation - Information Elements
Policy Enforcement Installation/Modification Confirmation (H-RAC -> A-RACF)
Request Originating Function Identifier Global unique Identifier for the Request Originating Function
instance.
Resource Reservation Session ID The reference is a unique resource reservation session
identifier in the scope of the Request Originating Function
Identifier.
Result (conditional, see notes 1 and 2) The result according to the type of the request.
NOTE 1: This Information Element is not generated by the H-RAC in response to a policy removal
request performed in Policy Enforcement Modification Request message.
NOTE 2: This Information Element is always generated and returned in the remaining cases, i.e. in
response to Policy Enforcement Installation Request messages, or in response to Policy
Enforcement Modification Request messages sent by the A-RACF to activate a pre-defined, but
not yet activated, Policy Rule; or to install and activate a new Policy Rule; or to modify Policy
Rule(s) previously installed and activated; or to deactivate Policy Rule(s).

5.2 CPN and Access Line Resource and Admission Control
For use cases UC-ALR-1 and UC-CRA-1, RACS requests resources from the CNG and the CNG itself reserves
resources inside the CPN and/or on the access line as a separate process. The resource and admission control steps
trigger the policy installation steps from UC-ALP-1 and UC-CPI-1 implicitly either with the admission control process
(single stage method) or upon a separate commit request (two-stage method).
5.2.1 Procedures
RACS requests resources from the CPN and/or access line by sending a request to and receiving a response from the
H-RAC whether resources are available. In case resources are available they become reserved with the response.
Depending on the used method, resources are immediately available with a successful response or the H-RAC requires
a succeeding commit request by the RACS to enforce the appropriate policies in CPN and on the access line. Those two
options are referred to in [i.2] as "single stage resource management model" and "two-stage reserve-commit
management model". The latter is depicted in figure 6.
H-RAC RACS
(1) Locate CNG
(2) Resource Request
(3) Admission
Control
(4) Resource Request Relpy
(5) Resource Commit Request
(6) Enforcement
Control
(7) Resource Commit Reply
Figure 6: Two stage high level CPN resource request/response flow
The required steps are as follows:
1) The RACS determines based on local policies whether a CNG is to be queried and then locates the CNG.
2) RACS requests resources from the CNG's H-RAC function.
3) The H-RAC performs the admission control process. Admission control is performed for access line resources
and if needed for intra CPN resources (see clause 7).
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4) The CNG replies to the RACS that resources have been reserved.
5) The RACS sends a commit request to the H-RAC.
6) The H-RAC enforces the appropriate policies on the access line interface and inside the CPN if needed.
7) The H-RAC confirms the resource availability to the RACS.
In case of using the single-stage method, steps 4) and 5) are not executed.
5.2.2 Elementary Functions
The required elementary function for the RACS beyond those defined in [i.2] are:
1) Determine based on local policies if the CNG needs to be contacted.
2) Locate the CNG and its H-RAC functional entity.
The required elementary functions for the H-RAC are similar to those of an A-RACF as defined in clause 6.2.2 of [i.2].
Table 3 lists the common elementary functions.
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Table 3: Required and optional functions in H-RAC common to x-RACF definitions in [i.2]
Acronym x-RACF Description from x-RACF H-RAC specifics H-RAC
Elementary Function (see [i.2])
(see [i.2])
AAoRFE Authentication and Authentication and authorization
R3 and authorization of the of the FE requesting resources. M
beyond Requesting FE
CGRC R3 Check global resource Check if the total of the requests Includes access line
and capabilities match the global resource and/or CPN M
beyond capabilities. depending on use
case
ACP Admission control process Derivation of a QoS profile and
check of the availability of M

resources for unicast and
(see note)
multicast services.
RRP Reservation of resources Resource reservation taking into
process account the resource
management scheme used in the
SPDF request, i.e. single-stage
M
resource management, two-stage
(see note)
reserve-commit resource
management, or authorize-
reserve-commit resource
management.
DITP Derivation and Installation of Derive and install of QoS
M
Traffic Policies parameters as part of L3/L2 traffic
(see note)
policies.
QMTD QoS and Priority Mapping - Mapping of the network QoS
Technology Dependent parameters to transport
M
(technology-dependent) QoS
parameters.
TDDP Technology Dependent Makes technology-dependent and
Decision Point resource-based admission
M
decisions for unicast and
multicast services.
MITP Modification and Installation Actions taken upon QoS handling
of new Traffic Policies process, e.g. by monitoring and O
controlling of access resources.
HMRP Handling of media request Ability to handle the media priority
M
priority received in the resource

reservation request.
QMTI QoS and Priority Mapping - Maps the service QoS
Technology Independent requirements and priority received
from the AF to network QoS M
parameters (e.g. Y.1541 class)
and priority.
GC Gate Control Controls the opening and closing
M
of a gate.
IPMC IP Packet Marking Control Decides on the packet marking
M
and remarking of traffic flows.
RLC Rate Limiting Control Decides on the bandwidth limit of
M
traffic flows (e.g. for policing).
HSRP Handling of service request Ability to indicate a service priority
priority level in the resource reservation M
request.
PPS Policy based path selection Ability to choose the best
appropriate path for the requested
service flow according to network
O
policy, the requestor class, the

quality requirements and network
resource status, and to indicate
the selected path to the RCEF.
NOTE: In case the admission control decision is delegated to a subtended FE in the CPN, this is not mandatory
for the delegating H-RAC FE.
To solve CPN-specific tasks, the following list of additional functions is to be provided by the H-RAC.
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Table 4: Required additional functions in H-RAC
Acronym Function Description Type of EF
NBR NAT Binding Report The H-RAC delivers as an
answer to the resource request
O
the NAT binding it has reserved
locally for each flow to the RACS.

5.2.3 Admission Control
The H-RAC performs admission control for the access line and/or inside the CPN following an admission control
procedure involving one or two steps depending on the operator's policy.
The H-RAC verifies that the available resources are compatible with the requested resources taking into account
existing reservations. Resource admission control performed by the H-RAC may involve subtended functional entities
inside the CPN in case the H-RAC does not have a full view of CPN and sessions therein.
5.2.4 Policy Installation
Upon receiving the commit request or implicitly with the reservation, the H-RAC installs the appropriate policies on the
network elements it is in charge of. This possibly includes the CNG but also network elements inside the CPN such as
switches, wireless access points or media transceivers.
5.2.5 NA(P)T Traversal Assistance
NA(P)T in the CNG currently works in a non-predictive way. Upon receiving the first packet of a media flow from
inside the CPN, the NAT binding is created. Thus, the NGN cannot know the IP address and port where media needs to
be sent to prior to receiving the first packet. Address latching on the BGF as defined in [i.2] and [i.8] is used to create
proper bindings after session setup to allow media to flow through the CNG NA(P)T. When using the two-stage
reservation method, the RACS can request the NA(P)T binding information from the CNG during the initial session
setup phase in order to avoid additional steps for NA(P)T traversal such as address latching.
5.2.6 Informational Elements
The required informational elements for the H-RAC in the use case for CPN and access line resource and admission
control are similar to those of the Rq reference point between SPDF and x-RACF as defined in clause 6.3.1 of
ES 282 003 [i.2] and the Rr reference point between x-RACFs as defined in clause 6.3.8 of ES 282 003 [i.2]. The
function of the H-RAC in the use case here is the one of an x-RACF connected to an A-RACF with a few additional
informational elements required. Table 5 lists required informational elements and indicates whether they are included
in Rq, Rr or if they are specific to the RACS-CPN interaction.
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Table 5: Resource Reservation Request - Information Elements
Resource Request (RACS -> H-RAC) Available in
Rq/Rr or new
Request Originating Global unique Identifier for the Request Originating Function instance. Rr, Rq (AF
Function Identifier identifier there)
Resource Reservation The reference is a unique resource reservation session identifier in the Rr, Rq
Session ID scope of the Request Originating Function Identifier.
Requestor Name Identifies the RACS client requesting the resources (e.g. name of an ASP Rr, Rq
or group of ASPs). In the case of A-RACF, This name corresponds to the
Requestor Name in a QoS profile provided by NASS (see note 1).
Service Class Service class requested by the SPDF. It reflects the service relationship Rr, Rq
between the x-RACF and SPDF owners. The set of Service Classes that
are offered to an SPDF is an administrative matter.
Service Priority (optional) The priority associated to the service request that defines the handling Rr, Rq
precedence by the receiving entity.
Charging Correlation Globally unique identifier for charging correlation purposes. Rr, Rq
...