摘要:
Efficient switched network multicasting techniques are provided. Incoming multicast packets are processed by a central forwarding engine (CFE) in a network switch to generate forwarding indices used to make forwarding decisions for the packets based upon whether the packets are special multicast control packets or data packets. Forwarding of the special multicast control packets is determined by the switch's network management processor (NMP), while data packets are forwarded based upon conventional bridge forwarding techniques.
摘要:
Efficient switched network multicasting techniques are provided. Incoming multicast packets are processed by a central forwarding engine (CFE) in a network switch to generate forwarding indices used to make forwarding decisions for the packets based upon whether the packets are special multicast control packets or data packets. Forwarding of the special multicast control packets is determined by the switch's network management processor (NMP), while data packets are forwarded based upon conventional bridge forwarding techniques.
摘要:
Efficient switched network multicasting techniques are provided. Incoming multicast packets are processed by a central forwarding engine (CFE) in a network switch to generate forwarding indices used to make forwarding decisions for the packets based upon whether the packets are special multicast control packets or data packets. Forwarding of the special multicast control packets is determined by the switch's network management processor (NMP), while data packets are forwarded based upon conventional bridge forwarding techniques.
摘要:
Provided are methods and apparatus that enforce zoning rules by separately employing source and destination information. In certain embodiments, information uniquely identifying network destinations is provided on a destination CAM. In these embodiments, each destination identified in the destination CAM has an associated zoning decision vector provided in a results memory. The vector provides specific zoning decisions (permit or deny transmission) for specific sources on the network. The specific zoning decision to be applied to a frame under consideration is selected from a zoning decision vector by using source information taken from the frame.
摘要:
A method of operating a switch for frames in a computer network uses one or more indicia of frame type designation found in the received frame to derive a virtual local area network (derived VLAN) value. Also, an indicia of the receiving port may be used in constructing the derived VLAN value. The switch then uses the derived VLAN value in making forwarding decisions. Broadcast domains in the computer network may then be controlled by forwarding in response to the derived VLAN value.
摘要:
According to the present invention, methods and apparatus are provided to improve the techniques and mechanisms for forwarding packets at a fibre channel switch. A combined area table/domain table (ATDT) is accessed using destination information associated with a fibre channel packet. Area/port or domain information can be used to address entries in the ATDT. Each entry provides one or more paths to a given destination. Traffic shaping, load balancing, and other policy based forwarding considerations can be applied.
摘要:
Methods and devices are provided for the efficient allocation and deletion of virtual output queues. According to some implementations, incoming packets are classified according to a queue in which the packet (or classification information for the packet) will be stored, e.g., according to a “Q” value. For example, a Q value may be a Q number defined as {Egress port number∥Priority number∥Ingress port number}. Only a single physical queue is allocated for each classification. When a physical queue is empty, the physical queue is preferably de-allocated and added to a “free list” of available physical queues. Accordingly, the total number of allocated physical queues preferably does not exceed the total number of classified packets. Because the input buffering requirements of Fibre Channel (“FC”) and other protocols place limitations on the number of incoming packets, the dynamic allocation methods of the present invention result in a sparse allocation of physical queues.
摘要:
A system enables efficient flow control in computer network. In the preferred embodiment, when an entity detects an impending full condition, it cuts short its transmission of the current frame that is being sent, and immediately sends a pause signal. The entity also deliberately corrupts the error detection signature of the cut-off frame to ensure that whatever portion of it that may have been sent is discarded. After sending the pause signal, the entity re-sends the cut-off frame in its entirety. Upon receiving a pause signal, the receiving entity cuts short the current frame being transmitted to the entity that sent the pause signal. The receiving entity also corrupts the correction value of this cut-off frame. The receiving entity suspends its transmission of frames to the entity that sent the pause signal for a period of time. When the pause period expires, the receiving entity re-sends the cut-off frame in its entirety, and resumes the transmission of frames.
摘要:
A mechanism for combining plurality of point-to-point data channels to provide a high-bandwidth data channel having an aggregated bandwidth equivalent to the sum of the bandwidths of the data channels used is provided. A mechanism for scattering segments of incoming data packets, called data chunks, among available point-to-point data channel interfaces is further provided. A decision as to the data channel interface over which to send a data chunk to can be made by examining a fullness status of a FIFO coupled to each interface. An identifier of a data channel on which to expect a subsequent data chunk can be provided in a control word associated with a present chunk of data. Using such information in control words, a receive-end interface can reassemble packets by looking to the control word in a currently processing data chunk to find a subsequent data chunk.
摘要:
Methods and devices are provided for the efficient allocation and deletion of virtual output queues. According to some implementations, incoming packets are classified according to a queue in which the packet (or classification information for the packet) will be stored, e.g., according to a “Q” value. For example, a Q value may be a Q number defined as {Egress port number ∥∥ Priority number∥∥ Ingress port number}. Only a single physical queue is allocated for each classification. When a physical queue is empty, the physical queue is preferably de-allocated and added to a “free list” of available physical queues. Accordingly, the total number of allocated physical queues preferably does not exceed the total number of classified packets. Because the input buffering requirements of Fibre Channel (“FC”) and other protocols place limitations on the number of incoming packets, the dynamic allocation methods of the present invention result in a sparse allocation of physical queues.