Configuring Multi-Gigabit Fabric Communication
Cisco 3900 series, Cisco 2900 series, and Cisco 1900 series ISRs use a multi-gigabit fabric (MGF) for
the new modules and interface cards to inter-communicate on the router. Legacy modules that support
Cisco High-Speed Intrachassis Module Interconnect (HIMI) also support the MGF. Next generation
module drivers integrate with the MGF to perform port configurations, configure packet flow, and
control traffic buffering. On the router-side, there are no user-configurable features on the MGF. All
configurations are performed from the module, which may or may not lead to changes on the MGF.
Modules and interface cards inter-communicate using the MGF on the router with or without CPU
involvement. Modules and interface cards that communicate without CPU involvement reduce load and
increase performance on the router. Modules and interface cards that do not utilize the MGF
communicate with the CPU using the PCI Express (PCIe) link.
The following sections describe module and interface card communication through the MGF:
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Restrictions for Module and Interface Card Communication
Cisco 1941W
The wireless LAN (WLAN) module is only supported on the Cisco 1941W ISR.
Maximum Number of Legacy Switch Modules
A maximum of two integrated switch modules are supported when a legacy module is present in the
system. In this scenario, the two switch modules have to be externally stacked.
Supported Slots, Modules, and Interface Cards
The following slots support communication through the MGF:
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Cisco 3900 Series, Cisco 2900 Series, and Cisco 1900 Series Integrated Services Routers Generation 2 Software Configuration Guide
Restrictions for Module and Interface Card Communication, page 211
Supported Slots, Modules, and Interface Cards, page 211
Cisco High-Speed Intrachassis Module Interconnect (HIMI), page 213
Viewing Platform Information, page 214
Service module (SM)
Enhanced high-speed WAN interface card (EHWIC)
Internal service module (ISM)
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