1、ETS 300 007 November 1991 UDC: 621.395 Key words: ISDN, packet-mode. Integrated Services Digital Network (ISDN); Support of packet-mode terminal equipment by an ISDN ETSI European Telecommunications Standards Institute ETSI Secretariat: B.P.152 . F - 06561 Valbonne Cedex . France TP. + 33 92 94 42 O
2、0 TF. + 33 93 65 47 16 Tx. 47 O0 40 F European Telecommunications Standards Institute 1 991 . All rights reserved. No part may be reproduced or used except as authorised by contract or other written permission. The copyright and the foregoing restriction on reproduction and use extend to all media i
3、n which the information may be embodied. Page 2 ETS 300 007:1991 WhiM every care has been taken in the preparation and publication of this doabment, errors in content, typographical or otherwise, may occur. If you have comments concerning its acmracy, please write to %TSI Standards Management Dept.“
4、 at the address shown on tha titk page. Page 3 ETS 300 007:1991 Contents Foreword 7 Introduction . 7 Normative references 8 1 Scope . 10 2 General service aspects 10 3 Reference configurations 11 Configuration when accessing PSPDN services (Case A) . 11 Configuration for the ISDN virtual circuit ser
5、vice (Case 8) . 13 3.1 3.2 4 Service aspects . 16 Access to PSPDN services (Case A) . 16 4.1.1 Service characteristics . 16 4.1.2 User access capabilities . 16 4.1.3 Basic rules 16 4.1.4 Notification CISSS ; . 17 Access to the ISDN virtual circuit service (Case B) . 17 Service characteristics . 17 4
6、.2.1 4.2.2 User access capabilities . 17 Access through the B-Channel 17 Access through the D-Channel 18 Notification classes for incoming calls . 18 No notification class . 18 Conditional notification class . 19 Unconditional notification class . 19 Information mapping from the CCTi Recommendation
7、X.25 incoming call packet to the ETC 300 102-1 message 19 4.3 Compatibility checking 19 4.1 4.2 4.2.2.1 4.2.2.2 4.2.3.1 4.2.3.2 4.2.3.3 4.2.3.4 4.2.3 5 Addressing and routing aspects . 20 Terminal interface selection 20 5.1 5.2 Access to PSPDN services (Case A) . 20 Channel type selection . 20 Addre
8、ssing scheme for outgoing calls 20 Access to the ISDN virtual circuit service (Case B) . 21 5.2.1 5.2.2 5.3.1 5.3.2 5.3 Channel type selection . 21 Addressing scheme for outgoing calls 21 6 Interworking with dedicated networ kc 21 6.1 6.2 Circuit-mode access to PSPDN services (Case A) . 21 Access to
9、 PSPDNs via virtual circuit service (Case B) . 21 7 Packet communications at the S/T reference point 22 7.1 Outgoing access 22 Circuit-switched access to PSPDN services (Case A) 23 Access to the ISDN virtual circuit service (Case B) 24 7.1.2.1 B-Channel . 24 7.1.2.2 D-channel . 25 7.2 Incoming acces
10、s 25 7.1.1 7.1.2 Page 4 ETS 300 007:lSSl 7.2.1 Access from PSPDN servicec (Case A) 7.2.1.1 General . 25 7.2.1.2 Channel negotiation . 26 Access from the ISDN virkral circuit service (Case 8) . 27 7.2.2.1 B-Channel . 27 7.2.2.2 D.Channel . 28 7.2.2 7.2.2.3 Call offering 28 7.3 Virtual call establishm
11、ent and release . 32 Link layer establishment and release . 32 Packet layer virtual call SENP and RELEASE . 33 7.4 Call clearing 33 7.3.1 7.3.2 7.4.1 B-Channel . 33 7.42 D-Channel . 34 Additional error handling informaiion . 34 Access to/frm the ISDN virtual circuit service (Case B) . 35 7.4.3 7.4.4
12、 Cause mappings 35 Access tofirom PSPDN (b) does not necessarily fully align with the available stage 1 description, which is still under preparation. Therefore, several stage 1 aspects may not be covered here or are covered in a different manner; (cl is not based on a stage 2 description as there w
13、as no stage 2 draft ETS available; (dl does not necessarily seek alignment with draft ETC 300 O99 25 since it introduces limitations when the Packet Handler (PH) is remotely located: (e) includes a description of terminal adaptor functions which are required to support a CCTTT Recommendation X.25 14
14、 DE (Data Terminal Equipment) which is normaliy outcide the scope of any comparable stage 3 access protocol specification. In producing this draft standard, the following considerations have been taken into account: (4 DTEs conforming to CCTTT Recommendation X.25 14 shall be used, at least during th
15、e evolution of Integrated Services Digital Network (ISDN) and possibly thereafter, in conjuncon with Packet Mode Bearer Services (PMBS) provided on an ISDN or via an ISDN using circuit switched bearer service to Packet Switched Public Data Network (PSPDNs); (b) the packet mode TEls conforming to ETS
16、 300 012 23 and ETS 300 O11 22 at reference points S and T shall be used in conjunction with PMBS provided by an ISDN or via an ISDN using circuit switched bearer service to PSPDNs; (cl the functions and protocol defined by this draft ETS shall allow the provision of the network service defined in C
17、CTTT Recommendation X.213 18; (dl the interworking function between an ISDN and a PSPDN is defined in CCTTT Recommendation X.325 21; (e) the demand access to PSPDNs is defined in CCTTT Recommendation X.32 WI; (0 the dedicated access to PSPDNs is defined in CCTTT Recommendation X.25 141. W 3404583 OO
18、Ll3023 772 W Page 8 ETS 300 007:1991 Normative references This ETS incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent a
19、mendments to, or revisions of any of these publications apply to this ETS only when incorporated in it by amendment or revisim. For undated references the latest edition of the publication referred to applies. 121 31 41 151 161 m 181 191 I31 1141 11 51 CCllT Recommendation E.163 (1988): “Numbering p
20、ian for th international telephone service“. CCITT Recommendation E.164 (1988): “Numbering plan for the ISDN era“. CCIT Recommendation E.166 (1988): “Numbering plan interworking in the ISDN era“. CCITT Recammendation 1.130 (1988): Wethod for the characterkaon of telecommunication services supported
21、by an ISDN and network capabilities of an ISDN. CCTTT Recommendation 1.330 (1988): “ISDN Numbering and addressing principles“. CCllT Recommendation 1.411 (1988): ISDN wer-network interfaas - Reference configurations11. CCITT Recommendation 1.430 (1988): “Basic usernetwork interface - Layer 1 specifi
22、cation“. CCITT Recommendation Q.931 (1988): “ISDN ucer-network interface layer 3 specification for basic call control“. CCTTT Recommendation V.25 bis (1988): lAutomatic calling and/or answering equipment on the General Switched Telephone Network (GSTN) using the 1ooSeries interchange circuits“. CCTT
23、TRecommendationX.1 (1988): International user Classes of service in public data networks and Integrated Scnrices Digital Networks (ISDNs)“. CCllTRecommendationX.10 (1988): Tategories of access for Data Terminal Equipment (DE) to public data transmiscion services. CCTTT Recommendation X.21 (1988): “I
24、nterface between Data Terminal Equipment (DE) and Data Circuit-terminating Equipment (DCE) for synchronous operation on public data networks“. CCllT Recommendation X.21 bis (1988): Yke on public data networks of Data Terminal Equipment (DE) which is designed for interfacing to synchronous V-series m
25、odems“. CCm Recommendation X.25 (1988): “Interface between Data Terminal Equipment (DE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit“. CCITT Recornmendation X.31 (1988): “Support of packet mode term
26、inal equipment by an ISDN“. Page 9 ETS 300 007:1991 CCTTT Recommendation X.32 (1988): “Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and accessing a packet switched public data network through a public switched
27、 telephone network or an integrated services digital network or a circuit switched public data network“. CCTi Recommendation X.121 (1988): tllnternational numbering plan for public data networks“. CCTTT Recommendation X.213 (1988): “Networks service definition for open systems interconnection for CC
28、TTT applications“. CCTTT Recommendation X.300 (1988): “General principles for intenivorking between public networks, and between public networks and other networks for the provision of data transmission services“. CCTTT Recommendation X.320 (1988): “General arrangements for interworking between Inte
29、grated Services Digital Network (ISDNs) for the provision of data transmission services“. CCTTT Recommendation X.325 (1988): “General arrangements for interworking between Packet Switched Public Data Networks (PSPDNs) and Integrated Services Digital Networks (ISDNs) for the provision of data transmi
30、ssion services“. ETS 300 011: “Integrated Services Digital Network (ISDN); Primary rate usernetwork interface Layer 1 specification and test principles“. ETS 300 012: “Integrated Services Digital Network (ISDN); Basic user- network interface Layer 1 specification and test principles“. ETS 300 058 (1
31、991): “Integrated Services Digital Network (ISDN); Call Waiting (CW) supplementary service Digital Subscriber Signalling System No. one (DSS1) protocol“. ETS 300 099: “Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)“. ETS 300 102-1 (1990):
32、 “Integrated Services Digital Network (ISDN); User-network interface layer 3 Specifications for basic call control“. ETS 300 103 (1990): “Integrated Services Digital Network (ISDN); Support of X.21, X.21 bis and X.20 bis based Data Terminal Equipments (DTEs) by an ISDN Synchronous and asynchronous t
33、erminal adaption functions“. ETS 300 125 (1991): “Integrated Services Digital Network (ISDN); User- network interface data link layer specifications Application of CCTi Recommendations Q.920A.440 and Q.921/1.441 II. 3404583 OOLiLO25 545 Page i0 ETS 300 OO7:1991 i Scope This stage three standard defi
34、nes usernetwork signalling requirements to support: a) the application of the ISDN circuit mode 8 ktiz structured 64 kbit/s unrestricted bearer senrice category for access to a Packet Switched Public Data Network (PSPDN); , b) the ISQN packet mode bearer senrices (both B and D channels); for the pan
35、-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T reference point or coincident S and T referem- point (as defined in CCTTT Recommendation 1.411 6, by means of the Digital Subscriber Signalling System number one (DSS1). Stage th
36、ree identifies the protocols and switching functions required to suppwt telecommunicathn sewices (see CCTTT Fkcommendaiion 1.130 r41). In order to aid the understanding and the interpretation of the signalling and protocol requirements and specifications, this standard also includes: - reference con
37、figurations aiming at providing guidance on the allocation of functionality in an ISDN supporting the above services; - a summary of the service aspects that may be expected from an ISDN conforming to this standard. This standard also specifies the mapping from the coincident S and T reference point
38、 to the R reference point, using a terminai adaptor to support existing X.25 DTEs. This standard has been written to support cases a) and b) at the coincident S and T reference point. In addition the access protocol provides the capability to support cass a) and b) also at the T reference point wher
39、e the services are offered to the user via a private ISDN. The mapping to an S reference point or R reference point via a private ISDN (e.g. combining NT2 and TA functional groupings) is not specified, aithwgh such a configuration is not precluded. The ISDN packet-mode bearer senrices (PMBS) provide
40、 the unrestricted transfer (without alteration) of user information in a packetised manner over a virtual circuit within the B and D channels at coincident S and T reference point. The ISDN circuitniode 64 kbit/s unrestricted 8 kiiz structured bearer senrices provide unrestricted information transfe
41、r between coincident S and T reference points (see CCITT Recommendation 1.41 1 SI). This standard is applicable to user and network equipment supporting case a or case b, to be attached at either side of a T reference point or coincident S and T reference points. 2 General service aspects Two main s
42、ervices for packet switched data transmission are defined fw packetmode terminais connected to the ISDN, namely: - Case A: access to a PSPDN (PSPDN senrices); - Case 8: use of an ISDN virtual circuit service. _ - - H 3404583 0041026 481 H Page 11 ETS 300 007:1991 In Case A an ISDN transparent circui
43、t connection, either permanent (Le., non-switched) or demand (Le., switched), is used. The corresponding ISDN bearer service is a 64 kbit/s service. The service available to the user is that of the PSPDN described in CCTTT Recommendation X.25 14 (permanent access) and CCTTT Recommendation X.32 IS (d
44、emand access), as well as in other CCTTT X-Series Recommendations (e.g., X.2, X.121). In Case B an ISDN virtual circuit service is used. In Case A only B-channel can be used to access the packet switched service at the user- network interface, while in Case B both B-and D-channels can be used. The d
45、etailed service aspects for both cases are described in Clause 3. This ETC covers the following procedures at the coincident S and T reference point: - B- and D- channel access on both basic and primary rate interfaces: - CCTTT Recommendation X.25 14 LAPB procedures on the B-channel and ETS 300 125
46、28 LAPD procedures on the D-channel. CCTTT Recommendation X.25 14 LAP procedures are not considered here: - CCTTT Recommendation X.25 14 packet layer procedures on both 8- and D- channels. In addition, this ETC defines the use of ETS 300 125 28 and ETS 300 102-1 26 procedures, when appropriate for t
47、he establishment and release of a physical path through the ISDN. 3 Reference configurations The configurations given below are the basis on which the support of CCTTT Recommendation X.25 14 DTEs and TEls by the ISDN should be standardised. Interworking considerations are defined in Clause 6. These
48、configurations are also the basis on which the support of packet mode TES by an ISDN has been standardised, since an X.25 DTE and its Terminal Adaptor FA) is always equivalent to a packet mode TE1 at the S/T interface. Therefore, every reference in this ETS to the combination of an X.25 DTE and its
49、TA should always be considered as being applicable to a packet mode TE1. However, some TEls may have more capability than that available from an X.25 DTE and its TA. Multiple X.25 DTE + TAC or TEls, or a combination thereof, may be supported at the customer premises. Multiple X.25 DTEs may be multiplexed at layer 3 by an NT2 onto a single B-channel. Multiple TAC or TEls are able to use the B-channel, one at a time, on a per-call basis. This ETS only applies to packet mode operation carried out independently on a single ISDN net
