Method and apparatus for limiting the number of build-up packets during the process of building up a routing address in a digital telecommunication network

摘要

The invention relates to a method for limiting the number of build-up packets during the process of building-up a routing address for the subsequent transmission of address-coded packets, the addresses of these packets being this said routing address, from a first to a second subscriber of a digital telecommunication network. This network comprises a plurality of switching nodes, a plurality of subscribers, a plurality of bearer channels connecting each switching node with at least one other switching node and with no subscriber, or with one or more of said subscribers, a plurality of routing words individually assigned to the bearer channels and a plurality of call numbers individually assigned to the subscribers. During the process of building-up a routing address the first subscriber despatches a build-up packet containing the call number of the called second subscriber, said build-up packet received by a first switching node is retransmitted through all bearer channels connected to this switching node, such retransmission being continued at each switching node upon reception of each build-up packet, thus the number of build-up packets increasing rapidly within the network. The method for limiting this number of build-up packets comprises at each switching node the storing of the call number of the second subscriber upon reception of a first build-up packet during a predetermined time interval starting with the reception of this first build-up packet, comparing during said time interval the call numbers contained in the subsequently received build-up packets with the call number stored, counting all of said subsequently received build-up packets with a call number corresponding with the call number stored, comparing respective count with a predetermined limiting value, and eliminating each of said subsequently received build-up packet, if said respective count is higher than said predetermined limiting value.