tailieunhanh - Mạng và viễn thông P29

Network Numbering and Addressing Plans Thenetworknumbering or addressingplanis an important part ofthenetworkrouting plan, because the network address is the identification used by a caller to identify the customer or network port to which he wishes to be connected. Based on the network address, switched connectionswithinalltypesofnetwork are basicnumbering and addressing schemes, and the principles that goalongwiththem | Networks and Telecommunications Design and Operation Second Edition. Martin P. Clark Copyright 1991 1997 John Wiley Sons Ltd ISBNs 0-471-97346-7 Hardback 0-470-84158-3 Electronic 29 Network Numbering and Addressing Plans The network numbering or addressing plan is an important part of the network routing plan because the network address is the identification used by a caller to identify the customer or network port to which he wishes to be connected. Based on the network address switched connections within all types of network are established. In this chapter we discuss the five basic numbering and addressing schemes and the principles that go along with them. These schemes are international telephone service ISDN numbering plan according to ITU-T recommendations and recently combined into one recommendation international public data network numbering scheme according to ITU-T recommendation international telex service numbering according to ITU-T recommendation addressing scheme for the message handling service ITU-T recommendations Internet addressing scheme THE INTERNATIONAL TELEPHONE NUMBERING PLAN The international telephone numbering plan was originally defined in 1964 by ITU-T s recommendation which laid down the principles of numbering pertinent to public telephone networks. It remains substantially the same but has recently been combined with the subsequent recommendation numbering for the ISDN era into a single recommendation . Recommendation defines the recommended prefixes for international calls 00 and trunk calls 0 the allocation of country codes and the maximum number length excluding international prefix 15 digits . Figure illustrates an number or network address. 513 514 NETWORK NUMBERING AND ADDRESSING PLANS international prefix 00 country code CO national significant number NSN trunk area code subscriber number maximum 15 digits structure of an international telephone .