Abstract: In one embodiment, a flow control module aggregates indications of queuing resource utilization at devices attached to a switching fabric within a router and broadcasts that information out of band to all devices attached to the same switching fabric. When the flow control module identifies congestion at one of the attached devices according to the indications, the module may also cause a throttling of traffic sent to the congested device in addition to sending the out of band indication of the congestion to all the attached devices. Flow control modules for each of the attached devices provide local interrupts for reducing outbound traffic to a congested device according to the identification of that remote congestion.

Abstract: In one embodiment, a flow control module aggregates indications of queuing resource utilization at devices attached to a switching fabric within a router and broadcasts that information out of band to all devices attached to the same switching fabric. When the flow control module identifies congestion at one of the attached devices according to the indications, the module may also cause a throttling of traffic sent to the congested device in addition to sending the out of band indication of the congestion to all the attached devices. Flow control modules for each of the attached devices provide local interrupts for reducing outbound traffic to a congested device according to the identification of that remote congestion.

Abstract: A system for selectively forming high-speed serial connections between various components of a network device that includes a multiplexing switch coupled a GE slot and to the high speed serial interfaces of a PHY and at least two network devices. The switch can be programmed to connect the serial interfaces of the two network modules to provide a high-speed, low-latency serial link between the two network modules. Alternatively, the serial interface of a network module can be connected to the GE slot to provide a high-speed, low-latency serial link between the network module and the GE slot.

Abstract: A communication controller is disclosed with a plurality of service modules including a redundant service module and with a mechanism for substituting the redundant service module for any one of the service modules. The communication controller includes a redundancy module that distributes communication signals to the redundant service module via a distribution bus coupled to the service modules. The distribution bus is alternatively used to distribute a high speed communication link to the service modules for improved physical connectivity.

Abstract: A communication interface with an expandable multilane cell bus that enables conversion of communication traffic received over a set of low speed or narrow band communication links according to a first communication protocol into a series of communication cells according to a second communication protocol. The cell bus enables concentration of the communication cells for transfer over a high speed communication link according to the second protocol. The communication interface includes a cell bus master that polls slave service modules while transferring communication cells to the service modules over a unidirection transmit portion of the cell bus and while receiving communication cells over a unidirection receive portion of the cell bus.