CONTENTS



		Page



1.	SECTION 1 - NETWORK FUNCTIONAL PRINCIPLES.......................    3



1.1	Recommendation I.310 - ISDN network functional principles.......    3



2.	SECTION 2 - REFERENCE MODELS....................................	 35



2.1	Recommendation I.320 - ISDN protocol reference model............	 35



2.2	Recommendation I.324 - ISDN network architecture................	 49



2.3	Recommendation I.325 - Reference configurations for ISDN 

	connection types.................................................	 64



2.4	Recommendation I.326 - Reference configurations for 	relative.network resource requirements.......................... 	 73



3.	SECTION 3 - NUMBERING, ADDRESSING AND ROUTING...................	 76



3.1	Recommendation I.330 - ISDN numbering and addressing 	principles......................................................	 76



3.2	Recommendation I.331 - Numbering plan for the ISDN era..........   85



3.3	Recommendation I.332 - Numbering principles for interworking 

	between ISDNs and dedicated networks with different 

	numbering plans.................................................   85



3.4	Recommendation I.333 - Terminal selection in ISDN...............	 90



3.5	Recommendation I.334 - Principles relating ISDN 

	numbers/subaddresses to the OSI reference model network layer 	addresses........................................................	112 



3.6	Recommendation I.335 - ISDN routing principles..................  118



4.	SECTION 4 - CONNECTION TYPES....................................	145



4.1	Recommendation I.340 - ISDN connection types....................  145



5.	SECTION 5 - PERFORMANCE OBJECTIVES..............................	166



5.1	Recommendation I.350 - General aspects of Quality of Service 

	and network performance in digital networks, including 	ISDNs...........................................................	166



5.2	Recommendation I.351 - Recommendations in other services          

	including network performance objectives that apply at 

	T reference point of an ISDN....................................  180



5.3	Recommendation I.352 - Network performance objectives for 

	connection processing delays in an ISDN.........................  180





1.	SECTION 1 - NETWORK FUNCTIONAL PRINCIPLES



1.1	Recommendation I.310



ISDN-NETWORK FUNCTIONAL PRINCIPLES































































FIGURE 1/I.310



ISDN network series of Recommendations





1.2	Services supported by an ISDN



	The concepts and the principles of an ISDN are described in RecommendationI.120. The services supported by an ISDN 
are given in the 

I.200-Series of Recommendations. A classification and the tools for the description of telecommunication services are spec-
ified in Recommendation I.210 according to the description method as given in Recommendation I.130. The network capabil-
ities to support these services are defined in the I.300-Series of Recommendations. The relationship between these 
Recommendations and some other relevant I-Series Recommendations is shown in Figure 1/I.310.





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	-	the low-layer functions (LLF) relate to the bearer services;



	-	the high-layer functions (HLF) together with the lower layer functions relate to the teleservices.



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	Recommendation I.324 introduces the functional grouping CRF (Connection Related Functions). The CRF can be local, 
national transit or international transit. EFs canbe associated with each of these.





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	-	Basic EFs: For each connection type, there are up to 8 BFGs to implement (see Table 1). Therefore each BFG is 
composed of basic EFs related to this connection type. However some basic EFs may be common to several connection 
types (e.g. "called number analysis" belonging to the BGF "routing").



	-	Additional EFs: Additional EFs form a common set of functional elements available to build up the various AGFs, 
and so to implement supplementary services.



	This grouping of EFs into sets of BGFs and AGFs is illustrated in Figure 6/I.310.





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