Abstract: 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.

Abstract: A device for checking bit errors occurring in datacells, used in switching equipment which forms part of a telecommunication system, includes an error discovery unit to detect bit errors occurring within an information carrying part of a datacell, and a counter and a processor unit to note the bit error in a bit error recording unit. The error discovery unit can also be used to amend the information carrying part and/or correct the bit error.

Abstract: 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.

Abstract: 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.

Abstract: The transfer of data packets are monitored in a line having various logical channels. For each logical channel there is a count value and at the arrival of a data packet, or in each time slot when the transmission on said line is time multiplexed, i.e., for each time when a packet could have arrived in a time multiplexed system, only the count value for a single channel is decremented. Then it is determined whether the received data packet, if there is one, is to be forwarded or is to be discarded by the comparison of a calculated value (F.sub.n) to a threshold value (T.sub.n) belonging to the channel to which the packet belongs. In the calculation of the value (F.sub.n), the number is used of those channels which have not been decremented after decrementing the channel to which the received packet belongs. In this way, the calculated value (F.sub.n) can be made to resemble the calculated value or level value, which is used in prior methods for handling loss of packets in a network.