8.3 Numbering System on the Telephone Network

The numbering system (addressing) is one of the fundamental characteristics of the network. It is currently being upgraded due to the emergence or expansion of new networks. Books [14, 46] can recommend books to readers who are interested in a detailed discussion of this issue.

In fixed telephone networks in the Russian Federation, there are two numbering plans - open and closed [46].

The numbering rules [46] are enshrined in ITU-T Rec. E-164, as revised in 1997. For the country to which its own code is assigned, or groups of countries having a common code (master numbering plan), the numbering structure shown in Fig. 2 is applied. 8.8.

Fig. 8.8. Number structure for geographic areas in accordance with ITU-T Recommendation designated E.164 (1997)

The national destination code can serve as a long-distance code or network selection function (for example, a long-distance and international). It has a variable length and is placed at the disposal of the national administration. Similarly, the number of digits of the subscriber number is determined. However, the number of digits cannot exceed 15 minus the country code.

With a closed subscriber numbering plan, they are assigned permanent numbers, and their value does not depend on the position of the caller (subscriber B). For example, with a closed numbering plan, any type of telephone connection (local, intrazone, long-distance) is established by dialing a national (significant) number. In the Russian Federation, when establishing an intrazonal telephone connection, a closed numbering plan is used, in which the number of decimal places in the national (significant) number is 10.

An open numbering plan is characterized by the fact that the number of characters depends on the connection route. When the numbering plan is open, the local telephone connection is established by dialing the local telephone number, and the intrazonal and long-distance telephone connections - by dialing the national (significant) number with the prefix “Mon”.

Starting from 2007, in accordance with the order of the Ministry of Information Technologies and Communications No. 142 dated November 17, 2006 [54], the principle of the numbering system of the Russian Federation is gradually changing.

The reasons for changing the numbering plans are mainly in the following points:

1. Previously, telecommunications networks belonged only to the state and represented a single network (Unified Automated Network) providing local, long-distance and international communication services. There are currently several private networks. This gave rise to the problem of choosing the operator who will provide communication services. In this case, a preliminary choice by the subscriber of such a company or a choice at each call is possible. This requires in the numbering the possibility of specifying the operator who provides the communication service.
2. In addition, the existence of a single network allowed numbering only by geography. Now networks have emerged that are focused on specific needs: for example, providing communication with enhanced security. Entering such services requires the introduction of appropriate signs into the numbering that are not related to the geographical location of the network, so that the subscriber can indicate what type of network he intends to use.
3. Changing the numbering for the first two reasons allowed us to take into account the practice of world numbering. For example, the use of intellectual services, free call for subscribers (called around the world "service 800"), the combination of some emergency services (rescue service), access to long-distance communication.

The numbering plan is based on the principle of zone numbering. Previously, within the framework of the Unified Automated Communication Network of the country, an area was understood as a part of the territory of the country in which subscribers had a single numbering. Currently, non-geographic numbering zones have been added to the concept of a zone. These are zones of networks of intellectual services, zones allocated for connecting technological equipment (channel checks and signaling equipment), mobile networks.

The zone is assigned a three-digit code.

For geographic areas, it is referred to as ABC.

For non-geographical areas, it is designated DEF.

Geographical zones, as a rule, are connected with the places of concentration of subscribers. These are cities, districts and territorial entities. Zones have a three-digit code that does not depend on the place where this outgoing number is dialed. For example, zones are the cities of St. Petersburg - code 812, Sochi - code 862. In the largest zones, the first of which is the Moscow region, the concept of "several zones" has been introduced. In this case, the numbering plan of the Moscow region itself represents several numbering zones.

Non-geographic areas may have one code or several DEF codes or use a part of the numbering allocated for one code.

Numbering in the geographical area uses a numbering format.

ABC a _b x ₁ , x ₂ , x ₃ , x ₄ , x ₅ ,

where ABC is the area code.

a _b x ₁ , x ₂ , x ₃ , x ₄ , x ₅ area code (zone numbering).

On the city network, only closed 5,6,7-digit numbering is used. With seven-digit numbering on local networks, the zone number is the subscriber number of this network.

When calling the subscribers of the regional center's GTS with 5-digit or 6-digit numbering, the local number of the subscriber must be supplemented with zonal (7-digit) numbers 22 or 2, respectively. With 5-digit numbering, the numbers 22 are typed as ab (ab = 22). In the six-digit numbering, a is used as 2 (a = 2). Sometimes, as an exception, the use of a closed numbering of a number with a different value is allowed on one network (for example, 5-6 or 6-7 characters, more, but not more than 11 characters).

Two code values, a = 0 and a = 8, are reserved for special services and long-distance communications. The remaining values ​​can be used for numbering.

To enter another zone, use the national prefix P _n (exit code for long-distance connection). Currently P _n = 8. In the future, there is a transition to P _n = 0.

To enter the international number, the international prefix P _mn . Currently, P _mn = 8-10. In the future, P _mn = 00.

If a zone contains several networks, then in order to reach a subscriber of another network in this zone, dial Pn 2 ab x ₁ , x ₂ , x ₃ , x ₄ , x ₅ .

On the rural network. Currently, both open and closed numbering can be used. In the future, only closed numbering is envisaged.

Local telephone subscribers, when using an open numbering system within their terminal (OS) or hub station (CS), establish a connection by dialing an abbreviated three-digit number, and for output to the central station (CS) and to other stations connected to the CA, a five-digit number. In this case, the numbering within the CA is always closed.

In non-geographic numbering zones, the seven-digit closed numbering is of the same type as in geographical: ab x ₁ , x ₂ , x ₃ , x ₄ , x ₅ .

Creation of groups of subscribers with a separate numbering plan is allowed. For outgoing communication, the prefix of the exit from the group (P _n ), which is often equal to 9, can be used. This index cannot be used as the first digit of the group.

To call subscribers of other zones, the dialing plan works.

Pn ABC ab x ₁ , x ₂ , x ₃ , x ₄ , x ₅

or

P _n DEF ab x ₁ , x ₂ , x ₃ , x ₄ , x ₅ .

If a service access code (KDU) is used, the format is

P _n KDU ab x ₁ , x ₂ , x ₃ , x ₄ , x ₅ .

When using carrier services in accordance with the modes, it is possible to use one of two numbering options.

With a preliminary choice of the operator who will provide services for long-distance and international communication, the numbering format is the same as we already discussed above.

When a carrier is selected, each call after the prefix is ​​followed by the operator's choice code XY. The value of Y is determined by the type of connection:

• international - YMn;
• intercity - Ymg.

To call the emergency and some reference services, an abbreviated numbering is used, containing 2-3 characters. In this case, the numbers use the first digit 0.

On all the networks of Russia, the emergency intelligence services are assigned the same two-digit numbers:

• fire service 01;
• police 02;
• Emergency Medical Services 03;
• gas network emergency service 04.

In the future, the number 112 will be used (unified rescue service). In the transition period there will be both numbering systems.

For access to the services of the information system of telecom operators that provide local telephone services within the same settlement, municipal district or city of federal significance using numbering from the resource of the same geographically defined zone, the format of the number “118” (x ₁ (x ₂ )) ".

For access to the services of the information system of a telecom operator providing local telephone services from other settlements, municipal districts or cities of federal significance using numbering from a resource of the same geographically defined zone, as well as from a resource of other geographically determined numbering zones and geographically not defined numbering zones, the format of the number of the type “Mon ABC118 (x ₁ (x ₂ ))” is applied.

For the Unified Automated Network of the country, numbers from 8-11 to 819 were reserved for intercity services (operators of international services, intercity and international services).

According to the new concept, the call for the help-inquiry services of long-distance and international telephone communication is carried out by dialing the national prefix (8 or, in perspective, 0) and three-digit numbers, for example, from 181 to 188, and for services in different languages ​​- from 190 to 198.

To call the reference information services of intercity, GTS and networks of regional centers of the rural telephone network with local abbreviated numbering using the automatic long-distance intra-zone network, full long-distance numbers should be used, built according to the principles listed below.

For calling a long-distance or intra-zone network of reference information services of the GTS of the regional center with 5-, 6-, or 7-digit numbering, a special code 99 of the one hundred thousandth group ab is allocated.

Calling services with two-digit numbering is done by dialing:

With double digit numbering

P _n - ABC 99Ox111 (where 0x is the number of the corresponding service)

With a three-digit numbering

P _n - ABC990x111 (where 00x is the number of the corresponding service).

Subscribers of other local networks of the same zone (intrazonal communication) should dial only a sign of intrazonal communication 2.

With double digit numbering

P _n - 2abOx111 (where 0x is the number of the corresponding service)

With double digit numbering

P _n - 2ab00x11 (where 00x is the number of the corresponding service)

11 (1) - additional signs to equalize the value of a long-distance or area number.

In the future, in the seven-digit numbering zone for calling special services, code 131UVX ₆ X _{7 was} proposed, where 1UV is the number of the corresponding service, and X6X7 defines the node of special services - CSS, which provides these services.

Local network subscribers of the same numbering zone will dial P _n 2 131UVX ₆ X ₇ .

In conclusion, we note that the new system and the new numbering plan are put into effect in stages:

• Stage I (2007) - transition to the use of a closed numbering plan when establishing intrazonal telephone connections and excluding from the local telephone network numbering plans telephone numbers with the first digit equal to "1".
• Stage II (2008) - the transition to use when establishing international telephone connections "P _mn = 00" and the establishment of intra-zone and long-distance connections "P _n = 0", the transition to the use of numbers like "1UV (x ₁ (x ₂ ) "for access to emergency and operational services, reference and information services of telecom operators and special services of local telephone networks.
• Stage III (2009) - the transition to the use of a closed numbering plan when establishing local telephone connections.

For those who are interested in more detailed numbering plans, we can say that a complete description of the numbering system with regard to mobile networks, signaling networks, the Internet, non-geographical areas and specific codes is contained in [46, 47].