Managing Memory Within a Local Telecommunications Network

The present invention relates in general to telecommunication systems and more particularly to a method and system for managing memory within a local telecommunications network.

Memory allocation in a telecommunications switching system is typically controlled by the message rate entering the switch and transport demands based on congestion rates. Heuristic analysis of switch demand has typically been used to assist in determining the proper allocation of memory for the transport of messages through the telecommunications switch. However, heuristic approaches lead to unfair memory allocation. Further, allocating memory based on the message rate may cause certain side effects that may hamper the efficient transfer of telecommunications information. Therefore, it is desirable to allocate memory within a telecommunications switch that is not determined by message rates or heuristic analysis.

In accordance with the present invention, a method and system for managing memory within a local telecommunications network are provided that substantially eliminate or reduce disadvantages and problems associated with conventional telecommunications systems.

According to an embodiment of the present invention, there is provided a method of managing memory within a local telecommunications network that includes associating a pool of buffers with a first local communication processor and a second local communication processor. A message-in buffer from the pool of buffers is associated with the second local communication processor. A message-out queue is associated with the first local communication processor. A buffer location is received at the message-out queue associated with the first local communication processor. The buffer location corresponds to the message-in buffer associated with the second local communication processor, with the message-in buffer associated with the second local communication processor containing a message destined for the first local communication processor. An empty buffer within the pool of buffers is assigned as a next message-in buffer associated with the second local communication processor in order that the second local communication processor can process a new message.

The present invention provides various technical advantages over conventional management systems within a telecommunications network. For example, one technical advantage is to efficiently manage memory within a local telecommunications network. Another technical advantage is to provide throttling at the local communication processor based on memory receive rates without denying access to the memory for other local communication processors. Yet another technical advantage is to provide access sharing of a memory for both local and remote communication processors. Still, another technical advantage is to put back pressure on the local communication processors when a destination processor is busy. Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description, taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, in which:

FIG. 1 illustrates a block diagram of a telecommunications network;

FIG. 2 illustrates a block diagram of a transporting node controller within the telecommunications network; and

FIGS. 3A-B illustrate a block diagram of how memory is managed by the transporting node controller within the telecommunications network.

FIG. 1 is a block diagram of a telecommunications network 10. Telecommunications network 10 includes a message transport network 12 that transfers telecommunication information among a plurality of subscribers 14. Each of the subscribers 14 receives and sends telecommunication information from and to an associated communication processor 16, respectively. Each communication processor 16 transfers telecommunication information to and from subscribers 14 either locally for locally situated subscribers such as subscriber 14a and subscriber 14b or remotely between a local subscriber 14a and a remote subscriber 14c. Communications processor 16 interfaces with a transport node controller 18 which supervises and controls the transfer of telecommunications information between subscribers 14 local to transport node controller 18 and between subscribers 14 local to transport node controller 18 and subscribers 14 remote from transport node controller 18.

FIG. 2 is a block diagram of transporting node controller 18. Transport node controller 18 includes a remote processor controller 20 that interfaces with remote communication processors 16 through message transport network 12. Transport node controller 18 also includes a local processor controller 22 that interfaces with local communication processors 16 in communication with local subscribers 14. Telecommunications information entering transport node controller 18, either remotely through remote processor controller 20 or locally through local processor controller 22, is temporarily stored in a buffer memory 24. Buffer memory 24 includes a pool of buffers 26 that store telecommunications information messages destined from one subscriber 14 to another subscriber 14 for either a remote or local transfer. Transport node controller 18 includes a controller and memory processor 28 that provides supervision and control of buffer memory 24, local processor controller 22, and remote processor controller 20. Local processor controller 22 and remote processor controller 20, in response to controller and memory processor 28, manage the pool of buffers 26 within buffer memory 24 to provide an effective and efficient transfer of telecommunication information within telecommunication network 10.

FIGS. 3A-B illustrate the management of buffer memory 24 by local processor controller 22 and remote processor controller 20. As shown in FIG. 3A, each local communication processor 16.sub.1-n and a remote communication processor 16.sub.r are assigned a buffer 26 from a pool of buffers within buffer memory 24. Buffers 26.sub.r and 26.sub.1-n assigned to local communication processors 16.sub.1-n and remote communication processor 16.sub.r are identified as Message-In buffers 26.sub.r and 26.sub.1-n, respectively. Message-In Buffer 26 receives a message from a subscriber 14 as processed by its associated local communication processor 16. Each local communication processor 16.sub.1-n and remote communication processor 16.sub.r is assigned a message-out queue 32.sub.r and 32.sub.1-n, respectively. Message-out queue 32 stores the location of a message-in buffer 26 containing a message destined for the local communication processor 16 associated with message-out queue 32. Also associated with each local communication processor 16 and remote processor 30, is a starvation queue 34 that is designed to hold the identity of a local communication processor 16 when there are no buffers available from the pool buffers within buffer memory 24.

In operation, local processor controller 22, through controller and memory processor 28, assigns a message-in buffer 26.sub.1-n to each of local communication processors 16.sub.1-n. Similarly, remote processor controller 20 assigns a message-in buffer 26.sub.r, through controller and memory processor 28, to remote communication processor 16.sub.r. From the pool of buffers within buffer memory 24. Upon receiving a message, local communication processor 16 processes the received message and routes the message MSG1 to its assigned message-in buffer 26. In the example illustrated, local communication processor 16.sub.2, processors message MSG1 receive from a subscriber 14 and places message MSG1 into its associated message-in buffer 26.sub.2. Local processor controller 22 determines the destination for message MSG1, in this instance local communication processor 16.sub.1, and places the address location for message-in buffer 26.sub.2 into message-out queue 32 of.sub.1 local communication processor 16.sub.1 corresponding to the destination for message MSG1. With message-in buffer 26.sub.2 now occupied with message MSG1, local processor controller 22 assigns a next message-in buffer 362 from the pool of buffers within buffer memory 24. Local communication processor 16.sub.2 is now ready to receive and process a second message that can be placed within next message-in buffer 36.sub.2.

Upon receiving a second message, MSG2, local communication processor 16.sub.2 processes message MSG2 for placement into next message-in buffer 36.sub.2. Local processor controller 22 determines the destination for message MSG2, in this instance, a subscriber 14 at local communication processor 16.sub.n. Local processor controller 22 stores the address location of next message-in buffer 36.sub.2 within message-out queue 32.sub.n associated with local communication processor 16.sub.n. Local processor controller 22 then assigns a new message-in buffer 46.sub.2 allowing local communication processor 16.sub.2 to receive and process a new message.

For a message MSG3 received and processed by remote communication processor 16.sub.r, remote processor controller 20 supervises placement of message MSG3 within message-in buffer 26.sub.r assigned to remote communication processor 16.sub.r. Remote processor controller 20 determines the destination for message MSG3, in this instance local communication processor 16.sub.1. Remote processor controller 20 places the address location of message-in buffer 26.sub.r containing message MSG3 into message-out queue 32.sub.1 associated with local communication processor 16.sub.1. Remote processor controller 20 then assigns a next message-in buffer 36.sub.r to allow remote communication processor 16.sub.r to receive and process a new message.

Remote processor controller 20 and local processor controller 22 will continue to assign message-in buffers 26 for the routing of messages within telecommunications network 10 until the situation occurs when there is no available buffer 26 within the pool of buffers of buffer memory 24.

Each message-out queue 32 is designed to hold address locations for a finite number of message-in buffers 26. The size of message-out queues 32 may depend on the design requirements of local processor controller 22 and remote processor controller 20 and desired system operation. For illustration purposes, the size of message-out queue 32, is assumed to be sufficient to hold two address locations for message-in buffers 26. As shown in FIG. 3B, for a new message MSG4 entering transport node controller 18 from local communication processor 16 and destined for local communication processor 16.sub.1, local processor controller 22 places message MSG4 into message-in buffer 26.sub.n associated with local communication processor 16.sub.n. In normal operation, local processor controller 22 would place the address location of message-in buffer 26.sub.n into message-out queue 32.sub.1 and assign a next message-in buffer 36.sub.n to local communication processor 16.sub.n. However, message-out queue 32.sub.1 is full and will not accept a new address location. In this situation, the identity of local communication processor 16.sub.n is placed into starvation queue 34. Local processor controller 22 then disables local communication processor 16.sub.n to prevent processing of new messages to and from subscribers 14 associated with local communication processor 16.sub.n. This disablement forces back pressure to be applied to local communication processor 16.sub.n and its associated subscribers 14 such that telecommunication network 10 operates based on the receiving rate of a destination local communication processor 16.

Enablement of local communication processor 16.sub.n may occur in several ways. A first mode of operation may have message-in buffer 26.sub.n be given a special flag or notation that is set to identify that local communication processor 16.sub.n associated with message-in buffer 26.sub.n has its identity placed into starvation queue 34 and has been disabled. When space becomes available within message-out queue 32, local processor controller 22 places the address location of message-in buffer 26.sub.n into the available space of message-out queue. The identity of local communication processor 16.sub.n remains in starvation queue 34 and local communication processor 16.sub.n remains disabled until the address location of message-in buffer 26.sub.n reaches the top of message-out queue 32.sub.1. Local processor controller 22 transfers message MSG4 from message-in buffer 26.sub.n to local communication processor 16.sub.1 for transfer to the destination subscriber 14. The special flag associated with message-in buffer 26.sub.n is cleared, message-in buffer 26.sub.n is reassigned to local communication processor 16.sub.n, the identity of local communication processor 16.sub.n is removed from starvation queue 34, and local communication processor 16.sub.n is enabled to process a new message. This first mode of operation prevents local communication processor 16.sub.n from rapidly oscillating between an enabled and disabled state that may effect reliability and operation of transport node controller 18.

In a second operating mode, local processor controller 22 may assign a next message-in buffer 36.sub.n to local communication processor 16.sub.n when the address location of message-in buffer 26.sub.n can be placed into available space within message-out queue 32.sub.1, indicating that a buffer is available for assignment. In this second operating mode, a special flag is not needed for message-in buffer 26.sub.n. The identity of local communication processor 16.sub.n is removed from starvation queue 34 and local communication processor 16.sub.n is enabled upon assignment of a next message-in buffer 36.sub.n. Though this second operating mode is less efficient in that local communication processors 16 may rapidly oscillate between enabled and disabled states, local communication processors 16 have equal access to available buffers such that a fair buffer allocation occurs among local communication processors 16.

In another operating mode, the address location for message-in buffer 26.sub.n may be placed in starvation queue 34 until such time that space becomes available within message-out queue 32.sub.1 associated with local processor 16.sub.1. Local processor 16.sub.n may be disabled or remain enabled and forced to internally queue up any further messages received and processed from subscribers 14 until such time that an empty buffer 26 can be assigned to local processor 16.sub.n. In this instance, local processor 16.sub.n would have to wait on local processor controller 22 for message transfer. Remote processor controller 20 operates similarly in assigning buffers 26 and with working with starvation queue 34 as local processor controller 22.

After controlling the placement of messages within buffer memory 24, local processor controller 22 and remote processor controller 20 also supervise and control the transfer of messages out of buffer memory 24. FIG. 3B shows the memory management for the transfer of messages from buffer memory 24. When local communication processor 16.sub.1 is ready to transfer messages destined for subscribers 14 associated with local communication processor 16.sub.1, local processor controller 22 checks message-out queue 32 associated with local communication processor 16.sub.1 for an address location of a message-in buffer 26. In this instance, local processor controller 22 identifies that message-out queue 32.sub.1 has the address location for message MSG1 at the top of the queue corresponding to message-in buffer 26.sub.2. Using the address location of message-in buffer 26.sub.2 holding message MSG1 from message-out queue 32.sub.1, local process controller 22 transfers message MSG1 from message-in buffer 26.sub.2 to local communication processor 16.sub.1 for processing and transfer to the destination subscriber 14. Upon completion of the transfer of message MSG1 to local communication processor 16.sub.1, local processor controller 22 reassigns message-in buffer 26.sub.2 back to the pool of buffers of buffer memory 24. Message-in buffer 26.sub.2 is now available to be assigned to any local or remote processor as determined by local processor controller 22.

In summary, a transport node controller provides for a fair and efficient allocation of memory among a plurality of local processors and the remote processor within a telecommunication network. Buffers within a pool of buffers of the buffer memory are assigned to local and remote processors based on availability and need without causing effects from one local subscriber to another.

Thus, it is apparent that there has been provided, in accordance with the present invention, a method and system for managing memory within a local telecommunications network that satisfies the advantages set forth above. Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein. For example, buffers may be assigned based on message priority, processor priority or congestion optimization. Other examples are readily apparent to one skilled in the art and may be made without departing from the spirit and scope of the present invention as defined by the following claims.