ETSI TR 183 068 V3.1.1 (2009-08)

Telecommunications and Internet converged Services and Protocols for Advanced Networks (TISPAN); Guidelines on using Ia H.248 profile for control of Border Gateway Functions (BGF); Border Gateway Guidelines

DTR/TISPAN-03202-NGN-R3

General Information

• Status: Published
• Publication Date: 11-Aug-2009
• Technical Committee: TISPAN 3 - TISPAN Protocols
• Current Stage: 12 - Completion
• Due Date: 20-Aug-2009
• Completion Date: 12-Aug-2009

Standards Content (Sample)

ETSI TR 183 068 V3.1.1 (2009-08)
Technical Report


Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
Guidelines on using Ia H.248 profile for
control of Border Gateway Functions (BGF);
Border Gateway Guidelines

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2 ETSI TR 183 068 V3.1.1 (2009-08)



Reference
DTR/TISPAN-03202-NGN-R3
Keywords
gateway, H.248, SIP
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3 ETSI TR 183 068 V3.1.1 (2009-08)
Contents
Intellectual Property Rights . 6
Foreword . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 8
3 Abbreviations . 9
4 Structure of this Technical Report . 9
Annex A: Illustration of Gate/Pinhole Concept. 10
A.1 General . 10
A.2 Relationships between gates and H.248 Streams . 10
Annex B: Void . 11
Annex C: Void . 12
Annex D: Illustration of an IP processing model for an H.248 (IP, IP) Context . 13
D.1 Example model . 13
D.2 Aspects of filter interaction . 15
D.2.1 Interaction between address latching and address policing . 15
Annex E: Guidelines for Ia-to-Gq' mapping . 17
E.1 Guidelines for Ia-to-Gq' mapping with regards to session-independent procedures . 17
E.1.1 Introduction . 17
E.1.2 Mapping guidelines . 17
E.1.2.1 Session-dependent procedures . 17
E.1.2.2 Session-independent procedures . 18
E.2 Guidelines for Ia-to-Gq' mapping with regards to bearer-specific events . 18
E.2.1 Introduction . 18
E.2.2 Mapping guidelines . 19
E.2.2.1 Guidelines for Specific Action AVPs . 19
E.2.2.2 Other AVPs . 19
Annex F: Bandwidth Reservation - Examples for Bandwidth Estimations . 20
F.1 Introduction . 20
F.1.1 Bitrate B in general. 21
F.1.1.1 Before service admission . 21
F.1.1.1a After service completion . 21
F.1.1.2 Transport efficiency . 21
F.1.2 Some important RACS principles . 22
F.1.2.1 Independence of layer 2 and layer 1 . 22
F.1.2.2 Awareness of IP version . 22
F.1.3 VPN Identifiers . 22
F.1.4 SDP "b=" line semantic in H.248 Ia profile versions . 22
F.1.5 Conclusion: ideal resource management model for resource "bitrate" . 22
F.2 Traffic aspects . 23
F.2.1 Quality of bitrate reservation . 23
F.3 Examples . 23
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4 ETSI TR 183 068 V3.1.1 (2009-08)
F.3.1 Examples for media-aware streams . 23
F.3.1.1 Example for G.711 . 23
F.3.2 Examples for media-agnostic streams . 24
Annex G: Illustration of BGF modes of operation . 26
G.1 Major SDP Information Elements for Media/Bearer/Resource Control in the BGF. 26
G.1.1 Example . 27
G.2 BGF modes driven by particular SDP lines . 27
G.2.1 SDP "c=" line . 27
G.2.2 SDP "m=" line . 28
G.3 BGF modes driven by configuration management . 28
G.3.1 Media-related modes . 28
G.3.2 Transport-related modes . 28
Annex H: Illustration of NAPT modes of operation . 29
H.1 NAPT types . 29
H.1.1 Remote NA(P)T devices . 29
H.1.2 MG-local NA(P)T function . 30
H.2 NAPT-full modes . 30
H.2.1 General case: non-symmetrical remote network addresses . 30
H.2.1.1 "Double" NAPT mode without explicit Local Source settings . 30
H.2.1.2 "Double" NAPT mode with explicit Local Source settings . 32
H.2.2 Special case: symmetrical remote network addresses . 32
H.2.2.1 "Double" NAPT mode without explicit Local Source settings . 33
H.2.2.2 "Double" NAPT mode with explicit Local Source settings . 34
H.3 NAPT-less . 34
H.3.1 Definition . 34
H.3.2 BGF (MG) behaviour for NAPT-less . 34
H.3.2.1 Handling of source transport address values {SA, SP} . 35
H.3.2.2 Handling of destination transport address values {DA, DP} . 35
H.3.3 Control methods of NAPT-less mode . 35
H.3.3.1 Method 1: mirrored H.248 LD and RD between the two H.248 IP terminations (stream endpoints) . 35
H.3.3.2 Method 2: omitted address information in H.248 LD and RD . 35
H.3.3.3 Method 3: explicit indication via H.248 Context Attribute . 35
H.3.4 NAPT-less examples . 36
H.3.4.1 "Double" NAPT-less mode, controlled via method 1 . 36
H.4 Mixed NA(P)T-full/NA(P)T-less modes . 36
H.4.1 Example of combination of Double-NAPT and NAPT-less . 36
H.4.2 Profile limitations . 37
Annex I: Illustration of "Protocol Layer Lx"-based Packet Processing BGF modes . 38
I.1 BGF modes - Technological Framework . 39
I.2 BGF modes - Control Framework . 40
I.3 Example BGF modes - RTP-based Applications . 43
I.3.1 Example application . 43
I.3.2 Transport-agnostic modes . 44
I.3.3 L4-port aware and transport-protocol agnostic modes . 46
I.3.4 Transport aware (= L4-port aware and transport-protocol aware) modes . 49
I.3.5 Media framing aware (= media-type aware, media-format agnostic, L4-port aware and transport-
protocol aware) modes . 52
I.3.5.1 Open items . 55
I.3.6 Media aware "RTP Transport Translator" (= media-type aware, media-format aware) modes . 55
I.3.7 Media aware "RTP Media Translator" (= media-type aware, media-format aware) modes . 58
I.4 Example BGF modes - TCP-based Applications . 61
I.4.1 Example application . 61
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5 ETSI TR 183 068 V3.1.1 (2009-08)
I.4.1.1 Mode discrimination . 62
I.4.2 TCP relay modes . 62
I.4.2.1 Unencrypted transport layer . 62
I.4.2.2 Encrypted transport layer using TLS . 64
I.4.3 TCP proxy modes . 65
I.5 Summary . 67
Annex J: Illustration of BGF Reporting of Protocol Layer Lx based Performance
Measurements . 68
History . 70

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6 ETSI TR 183 068 V3.1.1 (2009-08)
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

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7 ETSI TR 183 068 V3.1.1 (2009-08)
1 Scope
The present document defines guidelines for usage and implementation of border gateways (BGW), based on H.248
profile definitions for controlling such IP-to-IP gateways like ETSI TISPAN "H.248 Ia profile" specifications [i.1], [i.2]
and [i.3].
Figure 1 illustrates the architecture assumed in the present document.

Figure 1: Scope
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
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 indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
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8 ETSI TR 183 068 V3.1.1 (2009-08)
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ETSI ES 283 018 (Release 1): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); Resource and Admission Control: H.248 Profile
for controlling Border Gateway Functions (BGF) in the Resource and Admission Control
Subsystem (RACS); Protocol specification". - also known as "H.248 Ia Profile Version 1".
[i.2] ETSI ES 283 018 (Release 2): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); Resource and Admission Control: H.248 Profile
for controlling Border Gateway Functions (BGF) in the Resource and Admission Control
Subsystem (RACS); Protocol specification". - also known as "H.248 Ia Profile Version 2".
[i.3] ETSI TS 183 018 (Release 3): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); Resource and Admission Control: H.248 Profile
Version 3 for controlling Border Gateway Functions (BGF) in the Resource and Admission
Control Subsystem (RACS); Protocol specification". - also known as "H.248 Ia Profile Version 3".
[i.4] ITU-T Recommendation H.248.1 (2005): "Gateway control protocol: Version 3" including its
Amendment 1 (05/2008).
[i.5] 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.6] ETSI TS 183 017: "Telecommunications and Internet Converged Services and Protocols for
Advanced Networking (TISPAN); Resource and Admission Control: DIAMETER protocol for
session based policy set-up information exchange between the Application Function (AF) and the
Service Policy Decision Function (SPDF); Protocol specification".
[i.7] ETSI TS 181 018 (Release 2): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); Requirements for QoS in a NGN".
[i.8] ETSI TR 182 022 (Release 2): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); Architectures for QoS handling".
[i.9] IEEE 802.3: "Ethernet Working Group".
[i.10] ETSI TR 187 008 (Release 1): "Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN); NAT traversal feasibility study report".
[i.11] IETF RFC 5117 (2008-01): "RTP Topologies".
[i.12] draft-hunt-avt-rtcptrans-00.txt (2007-11): "RTCP Reporting by Translators".
[i.13] ITU-T Recommendation Y.1251 (08/2002): "General architectural model for interworking".
[i.14] Draft ITU-T Recommendation G.IP2IP: "Functionality and Performance of an IP-to-IP Voice
Gateway, optimised for the transport of voice and voiceband data".
[i.15] ITU-T Recommendation Y.1560 (09/2003): "Parameters for TCP connection performance in the
presence of middleboxes".
[i.16] IEEE 802.1: "Local Area Networks: Architecture & Overview".
[i.17] IETF RFC 1812: "Requirements for IP Version 4 Routers".
[i.18] IETF RFC 768: "User Datagram Protocol".
[i.19] IETF RFC 3550: "RTP: A Transport Protocol for Real-Time Applications".
[i.20] IETF RFC 3551: "RTP Profile for Audio and Video Conferences with Minimal Control".
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9 ETSI TR 183 068 V3.1.1 (2009-08)
[i.21] IETF RFC 4733: "RTP Payload for DTMF Digits, Telephony Tones, and Telephony Signals".
[i.22] IETF RFC 3142: "An IPv6-to-IPv4 Transport Relay Translator".
[i.23] IETF RFC 4734: "Definition of Events for Modem, Fax, and Text Telephony Signals".
[i.24] ITU-T Recommendation Draft H.248.64.
3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Admission Control
B2BIH Back-to-Back IP Host (mode)
B2BRE Back-to-Back RTP Endsystem (mode)
B2BTE Back-to-Back TCP Endpoint (mode)
BGF Border Gateway Function
CBR Constant Bit Rate
IP Internet Protocol
IPR IP router (mode)
LCD Local Control Descriptor
LD Local Descriptor (H.248)
LS Local Source
MALG Media Application lLevel Gateway
MG, MGW Media GateWay
MGC Media Gateway Controller
MP Measurement Point
MSRP Message Session Relay Protocol
NA(P)T Network Address (and Port) Translation
NAPT Network Address and Port Translation
NTE Network Telephone Events
PCI Protocol Control Information
PDU Protocol Data Unit
RD Remote Descriptor (H.248)
RFC Request For Comments (IETF)
RP Reporting Point
RS Remote Source
RTCP RTP Control Protocol
RTP Real-time Transport Protocol
RTPMTm RTP Media Translator mode
RTPTTm RTP Transport Translator mode
SDP Session Description Protocol
SDU Service Data Unit
SIP Session Initiation Protocol
SPDF Service Policy Decision Function
StAC Stream Admission Control
TCP Transmission Control Protocol
TLS Transport Layer Security
TRT Transport Relay Translator
UDP User Datagram Protocol
VBR Variable Bit Rate
4 Structure of this Technical Report
The present document inherits a structure based on annexes from the H.248 Ia profile specifications [i.1], [i.2] and [i.3].
The annex numbering was kept in order to be consistent with the old document versions of these specifications.
Any references from the annexes are related to H.248 Ia profile version 3 specification [i.3].
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10 ETSI TR 183 068 V3.1.1 (2009-08)
Annex A:
Illustration of Gate/Pinhole Concept
The purpose of this annex is the illustration of the H.248 Stream/Termination model by showing exemplary realizations
of gates for uni- versus bidirectional media flows.
A.1 General
Only point-to-point sessions are in scope of this H.248 Profile (see clause 5.4, TS 183 018 [i.3]). Interconnection of
individual H.248 Streams is based on the basic principle described in clause 7.1.6/H.248.1 [i.4]. The H.248 Multiplex
Descriptor is therefore not necessary (see clause 5.6.2, TS 183 018 [i.3]). The H.248 Topology Descriptor definition
includes individual H.248 Streams, but is also not necessary (see
clause 5.7.8, TS 183 018 [i.3]).
It has to be noted that all sessions have unicast media flows. Potential multicast applications are transparent for MG
point of view.
A.2 Relationships between gates and H.248 Streams
The realization of a gate is illustrated in figure A.1. There is a unidirectional media flow in that example, and there is a
single H.248 Stream per Termination. A H.248 Stream covers per definition a single bidirectional media flow
(clause 7.1.6/ITU-T Recommendation H.248.1 [i.4]). In this profile when RTP is used with RTCP, a single H.248
stream represents both RTP media and the corresponding RTCP flow. Media flows are interconnected by using the
same StreamID (here: StreamID equals to S1 for T1 and T2).
Example A1.1
IP H.248 IP H.248
Termination Termination
S1 S1
Gate
⇒
T1 IP H.248 IP H.248 T2
Stream Stream
H.248 Context
H.248 Context

Figure A.1: H.248 Context - Illustration of Gate, Stream and Terminations
The uni- or bidirectional application of an H.248 Streams is controlled via usage of Local Descriptor (LD) and Remote
Descriptor (RD). Figure A.2 shows a bidirectional session. There is again a single H.248 Stream per Termination. Gates
are direction-dependent, there are consequently two gates in this example.
Example A2.1
Gate
⇒
S1 S1
Gate
T1 T2
⇐
H.248 Context
H.248 Context

Figure A.2: H.248 Context Bidirectional Session using single H.248 Streams
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11 ETSI TR 183 068 V3.1.1 (2009-08)
Annex B:
Void
NOTE: This clause is present to be backwards compatible with the H.248 profile specifications in [i.2] and [i.3].
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12 ETSI TR 183 068 V3.1.1 (2009-08)
Annex C:
Void
NOTE: This clause is present to be backwards compatible with the H.248 profile specifications in [i.2] and [i.3].
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13 ETSI TR 183 068 V3.1.1 (2009-08)
Annex D:
Illustration of an IP processing model
for an H.248 (IP, IP) Context
The purpose of this annex is the illustration of a possible IP flow processing model. Such a model is helpful when
considering aspects concerning:
• location of a particular function within the (BGF) processing pipeline; or
• possible interactions between functions (see e.g. clause D.2).
It has to be noted that the model is just an example, not exhaustive concerning all possible functions with regards to
supported capabilities by this profile, and not related to any particular implementation.
D.1
...