Telefonaktiebolaget Lm Ericsson (publ)

Hans A Berghager

Leif M Larsson

Per E Sydhoff

Mats L Lindblom

Bjorn Inge Johansson

Bo Jerker Karlander

Hans M Nilsson

Raimo Kalevi Sissonen

Mikael Kundel

Jan S Wahlman

Peter C Lund

Astrid Berglund

Kenneth Browall

A change of switch plane operation is performed in a multi-plane cell switching node () which has a first switch plane (); a second switch plane (); and plural switch port interface units (). In response to detection of a fault in the active switch plane, the passive switch plane sends a plane change cell to the plural switch port interface units, and stops egress traffic flow from the second switch plane. Upon receiving the plane change cell, each switch port interface unit redirects traffic cells sent from the active plane to the passive switch plane. Each switch port interface unit then determines when traffic cells destined thereto have been flushed from the first switch plane, and changes its active switch plane designation (so that the formerly passive switch plane becomes the active switch plane) so that egress traffic flow can begin from the formerly passive (now active) plane to the respective switch port interface units.

Synchronous change of switchplane

The present invention provides interconnection links between modules in a switch node. A redundant physical link couples the modules and a dual state data packet routing tag is used to identify which link is active. A standard tag received from an application device is converted to the dual state data packet routing tag, after the data leaves the application device so the interconnection link routing is essentially invisible to the application layer.

Interconnection link redundancy in a modular switch node

A cell switch node () has a first switch plane (); a second switch plane (); a sender switch port interface unit (); and a receiver switch port interface unit (). The sender switch port interface unit sends maintenance cells to the receiver switch port interface unit via the first switch plane and the second switch plane. The maintenance cells are applied to the first switch plane and the second switch plane in a predetermined sequence. The receiver switch port interface unit detects an erroneous switch plane when the maintenance cells from the sender switch port interface unit do not arrive in the predetermined sequence.

Fault detection in multi-plane switch

Method of synchronizing signals and a device herefor

In a packet network for electronic transfer of data packets from one end station to another end station, there are, in the conventional way, a number of switch units. Each end station is connected to a switch unit, and the switch units perform the transfer of data packets along an established connection. The switch units are provided with switch ports on all of their connections. In these switch ports, a substitution is performed of labels of the data packets, both for data packets arriving to the switch unit and for data packets forwarded from the switch unit. The substitution prevents data packets belonging to different connections from having the same label and also offers distributed services in the data network. The data packet labels are constructed of a VPI field and a VCI field and, for data packets that arrive directly from or are sent directly to an end station, a GFC-field. In the substitution of the label of a data packet arriving to a switch unit, a table look-up is first performed in the associated switch port by way of the contents of the VPI field of the data packet. The result of the table look-up gives a direct information if the data packet belongs to a connection having a label comprising only a VPI field (VP connection), and then its contents are replaced by a record obtained in the table look-up. If the data packet has both a VPI field and a VCI field (VC connection), its VPI and VCI fields are replaced by new label portions obtained from a second table look-up.

Label handling in packet networks

A switch for the transfer of data packets comprises in the conventional way input ports and output ports and parallel switching planes, which are identical to each other. The switch establishes connections between input ports and output ports through the parallel switching planes. In each output port there is for each switching plane and each established connection a buffer accommodating at least one data packet. In the output port there is in addition a logical selection device for selecting data packets from the switch and from the different planes in such a way, that a data packet stream, which is as correct as possible, is obtained from the output port, and it selects in the first place data packets from a switching plane, which is the preferred plane at each instant. The selection device comprises a quality determining unit, which at each occasion determines the preferred plane by means of quality values for each plane. These quality values are determined by means of an evaluation of earlier data packets, which have arrived to the output port.

Method for handling redundant switching planes in packet switches and a

Identification of data packets in switching equipment included in a telecommunication system and known as a packet switch. A plurality of incoming links are connected to the switching equipment via first switch ports, and a plurality of outgoing links are connected to the switching equipment via second switch ports. The equipment also includes control and coupling devices required to connect an incoming link with an indicated link, where the indication of an outgoing link is initiated by signals in the form of one or more data cells occurring on an incoming link. Additional information in the form of additional bits is delivered to the data cell in the first switch port and the additional bits are given a configuration which corresponds to the address information in the data cell. The additional bits are removed in the second switch port. The additional bits include a category identification and/or a function identification.

Growing community of inventors

Alvsjo, Sweden

Hans A Berghager