SIST-TS TS 102 108 V4.1.1:2004

Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; H.248/MEGACO Profile for TIPHON reference point I3; InterConnect Function (ICF) control over reference point I3

Implementation of TIPHON Meta-Protocol using Extended MEGACO Package

Harmonizacija telekomunikacij in internetnega protokola prek omrežij (TIPHON), 4. izdaja - Profil H.248/MEGACO za referenčno točko I3 pri TIPHON - Krmiljenje funkcije medsebojnega povezovanja (ICF) prek referenčne točke I3

General Information

• Status: Published
• Publication Date: 31-Mar-2004
• ICS: 33.020 - Telecommunications in general
• Technical Committee: SPN - Services and Protocols for Networks
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2004
• Due Date: 01-Apr-2004
• Completion Date: 01-Apr-2004
• Ref Project: ETSI TS 102 108 V4.1.1 (2002-06) - Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; H.248/MEGACO Profile for TIPHON reference point I3; InterConnect Function (ICF) control over reference point I3

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS TS 102 108 V4.1.1:2004
01-april-2004
+DUPRQL]DFLMDWHOHNRPXQLNDFLMLQLQWHUQHWQHJDSURWRNRODSUHNRPUHåLM7,3+21
L]GDMD3URILO+0(*$&2]DUHIHUHQþQRWRþNR,SUL7,3+21.UPLOMHQMH
IXQNFLMHPHGVHERMQHJDSRYH]RYDQMD,&)SUHNUHIHUHQþQHWRþNH,
Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON)
Release 4; H.248/MEGACO Profile for TIPHON reference point I3; InterConnect
Function (ICF) control over reference point I3
Ta slovenski standard je istoveten z: TS 102 108 Version 4.1.1
ICS:
33.020 Telekomunikacije na splošno Telecommunications in
general
SIST-TS TS 102 108 V4.1.1:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS TS 102 108 V4.1.1:2004

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SIST-TS TS 102 108 V4.1.1:2004

ETSI TS 102 108 V4.1.1 (2002-06)
Technical Specification


Telecommunications and Internet Protocol Harmonization
Over Networks (TIPHON) Release 4;
H.248/MEGACO Profile for TIPHON reference point I3;
InterConnect Function (ICF) control over reference point I3

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SIST-TS TS 102 108 V4.1.1:2004
 2 ETSI TS 102 108 V4.1.1 (2002-06)



Reference
DTS/TIPHON-03028R4
Keywords
architecture, configuration, H.248, internet, IP,
megaco, network, protocol, telephony, VoIP
ETSI
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© European Telecommunications Standards Institute 2002.
All rights reserved.

TM TM TM
DECT , PLUGTESTS and UMTS are Trade Marks of ETSI registered for the benefit of its Members.
TM
TIPHON and the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members.
TM
3GPP is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners.
ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 3 ETSI TS 102 108 V4.1.1 (2002-06)
Contents
Intellectual Property Rights.5
Foreword.5
Introduction .5
1 Scope.6
2 References.7
3 Definitions and abbreviations.7
3.1 Definitions.7
3.2 Abbreviations.8
4 Scope of the H.248 ICF profile .8
4.1 Use of the H.248 ICF profile.9
4.2 Functionality supported by the Profile .9
4.3 Service capabilities supported.9
4.4 General note on compliance .9
4.5 Error handling.9
4.6 Security.10
5 Setting up of the controller-middlebox control interface .10
6 Use of the profile for the establishment of transport flows .10
6.1 Process used.10
6.2 Packages supported.11
6.3 Required H.248/MEGACO messages and parameters .11
6.3.1 Messages.11
6.3.2 Parameters.11
6.3.3 Error values.11
6.3.4 General notes on option use in H.248.12
6.4 Default transport setup procedure.12
6.5 Example flows for the use of this profile .13
6.6 QoS flows.13
6.6.1 QoS on flows through the middlebox .13
6.6.1.1 QoS policing of incoming flows .13
6.6.2 QoS on outgoing flows .13
6.6.2.1 ToS tagging of outgoing flows.13
6.6.2.2 RSVP.13
6.7 ToS filtering on incoming flows.14
7 Management operations.14
Annex A (normative): Mapping with meta-protocol .15
A.1 Code point mapping .15
A.1.1 Primitive mappings.15
A.1.2 Binary encoding.16
A.1.2.1 For an IP-based transport flow.16
A.1.3 Text encoding.16
A.1.3.1 For an IP-based transport flow.16
A.2 Error reasons.17
Annex B (normative): Meta-protocol to SDP mapping .18
B.1 Mappable fields.18
B.2 Specifying the OriginatorMpoA.19
B.3 Specifying QoS mechanism specific values.19
B.3.1 DiffServ Type of Service (ToS) value.19
ETSI

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 4 ETSI TS 102 108 V4.1.1 (2002-06)
B.3.2 RSVP.19
B.4 Unmappable fields.20
Annex C (informative): TIPHON template usage scenarios .21
C.1 Basic flow without address translation without source filtering .21
C.2 Basic scenario with address translation (the legacy mode) .24
C.3 Flow with address translation without source filtering .28
C.4 Flow without address translation with source filtering .33
C.5 Flow with address translation with source filtering .37
C.6 Explicit RTCP addresses with source filtering and address translation .42
C.7 Signalling: example flow for a H323 RAS control pin-hole.49
Annex D (informative): Options on the basic scenarios.52
D.1 Transport activation option .52
Annex E (informative): Bibliography.55
History .56

ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 5 ETSI TS 102 108 V4.1.1 (2002-06)
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 Specification (TS) has been produced by ETSI Project Telecommunications and Internet Protocol
Harmonization Over Networks (TIPHON).
Introduction
The present document defines technology mappings of the meta-protocol to reference points in the transport plane. It
specifies the technology mappings to reference point I3 as defined in TS 101 882 [2].
ETSI

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SCN Plane
SIST-TS TS 102 108 V4.1.1:2004
 6 ETSI TS 102 108 V4.1.1 (2002-06)
1 Scope
The present document describes a mapping of the meta-protocol for reference point I3, as described in annex D of
TS 101 882 [2], to the ITU-T Recommendation H.248 [1]/IETF MEGACO protocol, to produce an interoperable profile
(subset) of H.248/MEGACO augmented by the TPC Extension package defined in TS 101 332 [5].
It may be used for the control of equipment within an IP network such as Firewalls, Address Translators, Middleboxes
and also other network edge devices.
Originating/
Originating/Terminating Network FG Terminating/
Intermediate
Terminating
Originating
Network FG
Terminal FG
Serving Home
Gateway FG
Network FG Network FG
User
Service
CR QoSPE CR
QoSPE CR QoSPE
QoSPE profile
Profile
S3 S4 S3 S4 S3 S4
S4
S1 S2
S1
SC2’ SC2’ SC2’
SC SC
SC
SC SC
R1 R2
TREG SREG HREG
SC2
SC1 SC2 SC2
SC2
C1 C2 C2 C3
C1
CC CC CC CC CC
C2
C1 C3
C1 C2
BC BC BC
BC
BC
N2
N1 N2 N2 N3
M3
M1 M2 M2 M2
MC MC MC MC MC
T2 T2
T2
T1 T1
TU TPE TU TPE TU TPE
I6 I4 I6 I4
I6 I4
I1
I1
I2
I2
TRM TRM TRM TRM TRM
I3 I3
I5 I3 I5 I3
I3
I3 I5
ICF TF ICF TF ICF
ICF ICF TF ICF
Terminating/
Originating/
Originating
Core transport
Terminating
Ingress/Egress Egress/Ingress
Gateway FG
domain
Terminal FG
transport domain transport domain

Figure 1a: TIPHON architecture with reference point I3 highlighted
ETSI
r c
Se vi e
Bearer
Media
Transport Transport Transport
s Servi
flow Control ce
Call
control
Service
control

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SIST-TS TS 102 108 V4.1.1:2004
 7 ETSI TS 102 108 V4.1.1 (2002-06)
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• 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.
• For a non-specific reference, the latest version applies.
[1] ITU-T Recommendation H.248 (2000): "Gateway control protocol".
[2] ETSI TS 101 882: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Protocol Framework Definition; General (meta-protocol)".
[3] ETSI TS 101 314: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; Abstract Architecture and Reference Points Definition; Network
Architecture and Reference Points".
[4] IETF RFC 2327 (April 1998): "SDP Session Description Protocol".
[5] ETSI TS 101 332: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 4; Interface Protocol Requirements Definition; TIPHON Extended
H.248/MEGACO Package (EMP) Specification; ICF Control over Reference Point".
[6] IETF RFC 2205: "Resource ReSerVation Protocol (RSVP) - Version 1 Functional Specification".
[7] ETSI TS 101 329-3: "Telecommunications and Internet Protocol Harmonization Over Networks
(TIPHON) Release 3; End-to-end Quality of Service in TIPHON systems; Part 3: Signalling and
control of end-to-end Quality of Service (QoS)".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
charging: process of determining the amount of money a user shall pay for usage of a certain service
flow: single data stream, identified by a set of characteristic values (source address, source port, destination address,
destination port, protocol number)
functional entity: entity in a system that performs a specific set of functions
functional group: collection of functional entities within a domain
NOTE: In TIPHON systems functional groups are used to structure the necessary functionality to offer IP
telephony services across domains.
IP endpoint: device that originates or terminates the IP based part of a call
NOTE: Endpoints include H.323 clients, and IP telephony gateways.
IP network: packet transport network comprising one or more transport domains each employing the IP protocol
middlebox: firewall or NAT device which is coupled to a MIDCOM server, which offers the firewall/NAT services to
clients
network: telecommunications network that provides telecommunications services
ETSI

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 8 ETSI TS 102 108 V4.1.1 (2002-06)
protocol: set of semantics, syntax and procedures which govern the exchange of information across an interface
Switched Circuit Network (SCN): telecommunications network, e.g. Public Switched Telephone Network (PSTN),
Integrated Services Digital Network (ISDN), and General System for Mobile communications (GSM), that uses
circuit-switched technologies for the support of voice calls
NOTE: The SCN may be a public network or a private network.
TIPHON compliant: entity that complies with the mandatory requirements identified in the TIPHON requirements
documents together with compliance to the parts of the TIPHON specifications in which these requirements are
embodied
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
EMP Extended Megaco Package
GK GateKeeper
ICF InterConnect Function
IP Internet Protocol
MC Media Control
MB MiddleBox
QoS Quality of Service
RAS Registration Admission and Status
RSVP Resource reseVation Set-up Protocol
RTCP RealTime Conferencing Protocol
RTP RealTime transfer Protocol
SCN Switched Circuit Networks
SDL Specification and Description Language
TOS Type Of Service
TRM Transport Resource Manager
4 Scope of the H.248 ICF profile
The present document describes a profile of H.248 that mandates certain optional parts of the protocol and does not
mandate certain other options. Here the H.248 protocol is used to convey only flow properties to edge devices (ICFs) in
the transport plane. Used solely for this purpose, H.248/MEGACO, reduces to a small sub-set of the full protocol.
ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 9 ETSI TS 102 108 V4.1.1 (2002-06)
4.1 Use of the H.248 ICF profile

Controller
TRM
Reference Point I3
Middlebox
ICF

NOTE: This profile of H.248/MEGACO is used to control Middlebox devices in the transport plane. For the
purposes of the present document a Middlebox is defined as a physical implementation of an InterConnect
Function (ICF) TS 101 314 [3] and TS 101 329-3 [7]. A controller is defined as an implementation of
control functionality. The control relationship between a Middlebox and its controller is shown in figure 1b.

Figure 1b: Entities involved in Control over the I3 Reference point
4.2 Functionality supported by the Profile
The I3 reference point controls the ICF functions in a transport domain and will be under the control of the operator or
administrator of that domain. Instructions from the TRM (here the controller) to the ICF will relate to admission control
in the case of firewalls, network addresses in the case of Address Translators or control signals for QoS mechanisms
such as RSVP or DiffSDerv.
4.3 Service capabilities supported
TIPHON Release 4 service capabilities supported by the profile are basic bearer and QoS bearer set-up.
4.4 General note on compliance
Any options in the H.248 protocol not mentioned in the present document MAY be supported by the Middlebox or
controller, however are outside the scope of the present document.
4.5 Error handling
General use of the error codes can be found in clause A.2.
If an H.248 information element is received (descriptor or parameter), which is not specified in this profile, the receiver
shall ignore the information element and act as if the information element were not received.
If an unknown H.248 command or an information element not specified in this profile is received, the receiver shall
ignore the command and send an appropriate error (443 - unsupported or unknown command or 444 - unsupported or
unknown descriptor, 445 - unsupported or unknown property, 446 - unsupported or unknown parameter).
If an H.248 command with a mandatory information element missing is received, the receiver shall act as if the
information element was received carrying the default values, or reject with the appropriate error message if there is no
default value specified in the H.248 standard.
ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 10 ETSI TS 102 108 V4.1.1 (2002-06)
If an H.248 information element is received with syntactically invalid contents the receiver shall:
• if the information element is optional, ignore the information element; or
• if the information element is mandatory, act as if the information element was received correctly coded carrying
the default values and reject/fail if there is no default value specified in the standard.
If an H.248 information element is received with a value not allowed within the context of the present document, the
receiver shall:
• if the information element is optional, pass on, but otherwise ignore the information element; or
• if the information element is mandatory reject/fail.
NOTE: The security policy of an operator's network or the security policy implemented in a network element may
override the error handling as described above.
4.6 Security
Security issues associated with the use of this profile are outside the scope of the present document. It is intended that
they will be included in future releases of the present document.
5 Setting up of the controller-middlebox control
interface
Clause 11 of ITU-T Recommendation H.248 [1] shall apply without restrictions. This may change in future releases of
the present document.
6 Use of the profile for the establishment of transport
flows
The basic messages of H.248 used in this profile are here defined as well as certain H.248 packages. This clause
describes the messages used in the profile.
6.1 Process used
This clause provides the mapping of the flows in TS 101 882 [2] annex D, to H248 message flows. The parameter and
error reason definitions in TS 101 882 [2] annex D are aligned to ensure interoperability of these values across the
mappings of these reference points. In general each of the primitives defined on the T/I reference points in
TS 101 882 [2] each map to one or more commands in H.248. General note on source filtering used in the scenarios
SDP (see RFC 2327 [4]) specifies in clause B.2.1 a means for specifying unicast sessions. This provides the means to
encode the originator MpoA. In clause B.2 it is shown how the recvonly and send only attribute are used for specifying
the sender side behaviour of media flows.
ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 11 ETSI TS 102 108 V4.1.1 (2002-06)
6.2 Packages supported
The following packages shall be supported in this profile:
• Generic package (ITU-T Recommendation H.248 [1], clause E.1)
• Base Root package (ITU-T Recommendation H.248 [1], clause E.2)
• Network package (ITU-T Recommendation H.248 [1], clause E.11)
• EMP package TS 101 332 [5]
• If RTP statistics are to be supported, the RTP package (ITU-T Recommendation H.248 [1], clause E.12)
6.3 Required H.248/MEGACO messages and parameters
Annex A describes the codepoint mapping between H.248/MEGACO and the TIPHON meta-protocol TS 101 882 [2].
From this mapping follows that the following elements from H.248/MEGACO are to be supported.
6.3.1 Messages
• TransactionRequest.Add
• TransactionReply.Add
• TransactionRequest.Modify
• TransactionReply.Modify
• TransactionRequest.Subtract
• TransactionReply.Subtract
6.3.2 Parameters
• ContextId
• LocalDescriptor
• RemoteDescriptor
• TerminationID
6.3.3 Error values
• 411 – The transaction refers to an unknown ContextId
• 412 – No ContextIDs available
• 430 – Unknown TerminationID
• 432 – Out of TerminationIDs or No TerminationID available
• 432 – Put of terminationIDs or no terminationID available
• 433 – Termination ID is already in a contect
• 444 – Unsupported or unknown descriptor
• 510 – Insufficient resources
• 526 – Insufficient bandwidth
ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 12 ETSI TS 102 108 V4.1.1 (2002-06)
6.3.4 General notes on option use in H.248
The TIPHON semantics require that when multiple alternatives are returned by the Middlebox to the controller for a
termination the Middlebox shall support whichever one the controller chooses. Failure to support parameters for a
termination offered earlier is considered a fault.
H.248 does not have semantics as strict as those prescribed by TIPHON. To align the semantics, ReserveGroup needs
to be set for all alternative transport flow descriptions that are requested from the Middlebox and that ReserveValue
needs to be set for all request where the Middlebox is given the choice to provide flow descriptions.
The optional ModemDescriptor, MuxDescriptor. EventsDescriptor, DigitMapDescriptor, AuditDescriptor are not used
in this profile.
A transaction level timer shall be provided.
The flows in TS 101 882 [2] use a InvokingControllerReference, is mapped to StreamID in H.248.
The contextID is a value that is local to the Middlebox-controller relationship and is not mapped to the meta protocol.
The TIPHON type trReservedTransportReference and trEstablishedTransportReference shall be mapped to the
H.248 TerminationID.
Code point mapping for the Local and Remote Descriptors is provided in the annexes.
6.4 Default transport setup procedure
The transport plane allows reservation and allocation of resources for transport of a packet stream (e.g. to reserve
processing capability in routers and on links between them). See TS 101 882 [2] for a full definition of the primitives
involved .
NOTE: The following text is derived from the SDL in TS 101 882 [2]. Should there be discrepancies between
TS 101 882 [2] and the present document, the text in TS 101 882 [2] shall take precedent.
The transport element shall establish the transport resources required to support the transport flows required. If so
required, the transport elements shall establish a QoS controlled transport capability in accordance with the QoS
parameters identified.
Step TS 101 882 [2] Primitive meaning
MC layer decides it needs transport

TransportReservationRequest
1 asks the ICF/TRM to support it with a QoS-enabled transport stream and
wants to know what parameters it can support there.
2 TransportReservationConfirm the ICF/TRM acknowledges to the MC, providing the possible bearer
characteristics for the MC to decide upon. The MC-entity hereby commits
to provide the flows as identified in this message.
 The MC answers to BC….
3 TransportEstablishementRequest the MC informs the ICF/TRM of the choice.
4 TransportEstablishmentConfirm the ICF/TRM acknowledges the establishment of the transport flows.
5 TransportReleaseRequest The ICF/TRM is requested to release the transport flows.
6 TransportReleaseConfirm The ICF/TRM confirms the release of the transport flows.

ETSI

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SIST-TS TS 102 108 V4.1.1:2004
 13 ETSI TS 102 108 V4.1.1 (2002-06)
6.5 Example flows for the use of this profile
Annexes C and D provide examples of the use of this profile for firewall control. The Middlebox can operate in several
scenarios, these scenarios describe how the generic service offered over the T2 and I3 reference points can be used to
achieve certain specific goals.
Annex C describes the following examples:
• C.1 Basic scenario;
• C
...