A method for dynamically allocating buffers to virtual channels in an asynchronous network

摘要

In an asynchronous transfer mode (ATM ) network addressable buffers are used to store data packets prior to their transmission over a virtual channel. A memory pool comprising a plurality of addressable buffers in the form of a shared dynamic random access memory (DRAM) is used. The total number of buffers in use is monitored and provided this remains below a threshold level Tg buffers will be allocated when required. When the threshold Tg is exceeded the allocation of buffers to each virtual channel is restricted to the corresponding threshold level T1, T2, T3. Any new data for a channel operating above its threshold will be discarded or flow control initiated. This prevents heavily loaded comparatively slow channels from using too many buffers and faster channels from becoming starved of memory. The thresholds can be programmed and may be selected on the basis of channel usage and priority. Each channel may operate one or more thresholds.