Multitrunk ATM termination device
First Claim
1. A termination device for connection to a group of TDM (time division multiplexed) links comprising:
- an interface circuit for receiving an incoming cell stream forming one or more virtual channels, a buffer memory for storing incoming cells at memory locations identified by pointers;
a pointer queue for each virtual channel, said pointer queue indicating the memory locations of queued cells in each channel;
a control unit for interrogating the pointer queue and assigning the next incoming cell to the next free memory location for the associated channel, a scheduler selectively operable to sequentially assign cells from each queue in said buffer memory either to individual links or to a group of links forming an inverse multiplexed group; and
a per link output circuit for placing cells from said memory locations on said links to form outgoing virtual channels.
2 Assignments
0 Petitions
Accused Products
Abstract
A termination device for connection to a group of TDM (time division multiplexed) trunks is capable of sending cells over one or more links either individually or as part of an inverse multiplexed group. The device includes a Utopia interface for receiving an incoming cell stream, a buffer for storing incoming cells at specific memory locations identified by pointers obtained from a queue of available pointers, a round robin scheduler for sequentially assigning cells to links forming an IMA group or individually in the UNI mode, and a pointer queue for each channel address, the pointer queue indicating the location of the next cell to be transmitted for each virtual channel. An adaptive shaper determines when a stuff cell is inserted and a per link output circuit places cells on the links, which can operate in CTC or ITC mode. The device can operate in mixed mode where up to four IMA and/or up to eight UNI channels can be supported concurrently. The links assigned to the IMA or UNI channels is programmable.
-
Citations
16 Claims
-
1. A termination device for connection to a group of TDM (time division multiplexed) links comprising:
-
an interface circuit for receiving an incoming cell stream forming one or more virtual channels, a buffer memory for storing incoming cells at memory locations identified by pointers;
a pointer queue for each virtual channel, said pointer queue indicating the memory locations of queued cells in each channel;
a control unit for interrogating the pointer queue and assigning the next incoming cell to the next free memory location for the associated channel, a scheduler selectively operable to sequentially assign cells from each queue in said buffer memory either to individual links or to a group of links forming an inverse multiplexed group; and
a per link output circuit for placing cells from said memory locations on said links to form outgoing virtual channels. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A termination device for connection to a group of TDM (time division multiplexed) links and capable of receiving streams of cells forming a virtual channel over one or more of said trunks, said cell streams arriving on said individual links or on a plurality of said links forming an inverse multiplexed ((MA) group, comprising:
-
a per link input circuit for receiving incoming cell streams on said links;
a per link cell delineation circuit for delineating incoming cells;
a per link means for segregating control cells from user cells, a per group rate recovery block to generate the IDCR (MA Data Cell Rate);
a buffer memory for storing incoming cells of an IMA group at specific memory locations;
a per group inverse scheduler controlled by the IDCR and for arranging incoming cells of an IMA group in the correct order;
an output circuit for outputting cells to a receiving device through an interface; and
a memory controller selectively operable to direct incoming cells to said memory in an inverse multiplexing mode or to said output circuit in a UNI mode. - View Dependent Claims (12, 13, 14, 15, 16)
-
Specification