RU2477005C2 - Three-layered multiring structure of data transfer network - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: three-layered multiring structure of a data transfer network with double connections between units of double bidirectional rings, with the purpose to simplify routing and to increase vitality of measurement and control systems, has a hierarchical layered structure with double rings, with two and more links between rings, at the same time routing of packets is carried out along layers from a ring to a ring using a non-variable table of codes of packets transition from a layer to a layer, and the packet has a certain common format.

EFFECT: provision for increasing vitality of a network and universality of applying networks of different sizes, simplified routing of packets on the basis of a table of transitions.

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Description

Technical field

The invention relates to computer technology and is used in the construction of networks for measuring and control systems.

State of the art

The closest prototype is the SerialExpress interface network project (David V. James, David V. Gustavson, Balint Fleischer. Serial Express-A High-Performance Workstation Interconnect. IEEE Micro Vol. 18, No. 3 (May. 1998), pp. 54- 65. DOI = http: //dx.doi.org/10.1109/40.683105; P2100 SerialExpress - A Scalable Gigabit Serial Bus Draft 0.788, February 18, 1998 SCIzzL, ftp://ftp.SCIzzL.com/u/SClzzL/P2100 / SerExp (site encoded); K.E. Erglis. Interfaces of open systems. Training course. Hot line - Telecom, M. - 2000, p. 212). Based on this prototype, the ResilientPacketRing standard ("Resilient Packet Ring IEEE Standart 802.17-2004" June 2004, http // www.ieee802.org / 17) was created, which is optimized for critical information systems for data transmission over distances of several thousand kilometers.

Disclosure of invention

The invention is a hierarchical structure of a three-layer data transmission network (see Fig. 1), where each layer contains one or more bidirectional rings (101, 102, 103). The highest in the hierarchy is the layer with the number "0", the middle with the number "1", the lowest - with the number "2". Each ring has one or more connectives with rings of other layers for data transmission between them (104, 105, 106). The optimal number of layers for building large measurement and control systems is three, for medium and small systems - two layers and one layer, respectively.

A double ring consists of two rings A and B. A bidirectional ring (see Fig. 2) is a set of nodes 201 interconnected by cables - internodal connections with double connections 202 for transmitting data in opposite directions. The nodes are defined in patent RU No. 2449485 C1. Inter-nodal connections, which serve to transfer packets clockwise, together with nodes form a ring A 203, and those used to direct packets counterclockwise form a ring B 204.

In the process of converting the ring into a chain of nodes, rings A and B are closed at the nodes located near the rupture of the ring.

Such ring structures when damaged nodes 201 or connections 202 are converted into a chain of nodes (see figure 3), continuing the correct data transfer.

The presence of two rings is the first level of redundancy, which increases the survivability of the system.

Rings in a network are connected by one or more ligaments (link channels). Practical is the use of two bundles that reserve each other at the second level of redundancy.

The third level of redundancy is ring duplication for packet transmission. At the second and third levels of redundancy, multiple reservation of rings and ligaments is possible.

Such multi-level redundancy provides network survivability. The term "survivability" means the ability of the system to perform the assigned functions or, at least, the basic functions during partial destruction of the system caused by external factors, such as destruction in battle. Vitality is not quantifiable.

Survivability should not be replaced by the term "reliability". Reliability is the likelihood that the system will function properly for the intended life under certain environmental conditions.

Information on the network is transmitted in the form of packets for which a standard format is defined (see figure 4).

The packet consists of a header 401, transmitted payload 402, a check symbol 403.

The packet header field defines the address field of the receiving node, as well as the address field of the sending node and routing information for the packet to go over the network.

The node address consists of:

- two bits that define the layer (layer "0" - system, layer "1" - intermediate, "2" layer - peripheral in the network);

- 8 bits to determine the address of one of two hundred and fifty-six rings in the layer;

- the remaining 6 bits determine the address of one of the sixty-four nodes in the ring.

Sensors and executive bodies are connected to the application circuits of the unit. These circuits send commands and measurement data to other nodes in packets over the network.

When transferring packets from the peripheral layer through the intermediate layer to the system layer, it is sufficient to use only the full address of the destination node (in Fig. 1, from layer "2" to layer "1" to layer "0").

When transferring packets from the system layer 101 to the peripheral layer 102 or 103, it is necessary to have the layer codes in the header (see Fig. 5) and the ring address in the intermediate layer indicated in the header field intRingld (410), since the ring of the system layer 101 can be connected with several rings of the intermediate layer 102. A table with transition codes for layers (see FIG. 5) takes into account all possible transitions through layers 501. The columns of the table always indicate the initial layer S 502, where the ring with the node sending the packet and intermediate layers is located - s (406, 407, 408, 409).

Claims (1)

A three-layer multi-ring structure of a data transmission network with double connections between nodes of double bidirectional rings, which differs, in order to simplify routing and increase the survivability of measuring and control systems, by a hierarchical layered structure with double rings, with two or more links between rings, the way packets are routed by layers from ring to ring using an immutable table of codes for transitioning packets from layer to layer and defined by the general format of the package.

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