DCFM Enterprise User Manual (53-1001775-01, June 2010)
DCFM Enterprise User Manual 379
53-1001775-01
FCIP trunking
16
FCIP trunking
FCIP Trunking is a method for managing the use of WAN bandwidth and providing redundant paths
over the WAN to protect against transmission loss. This feature is available only on the 8 Gbps
extension switches and 8 Gbps extension blades. Trunking is enabled by creating logical circuits
within an FCIP tunnel. A tunnel may have multiple circuits. Each circuit is a connection between a
pair of IP addresses that are associated with source and destination endpoints of an FCIP tunnel,
as shown in Figure 149. Each circuit represents a portion of the available Ethernet bandwidth
provided by the GbE ports that are connected to the WAN.
FIGURE 149 FCIP tunnel and FCIP circuits
Design for redundancy and fault tolerance
Multiple FCIP tunnels can be defined between pairs of 8 Gbps extension switches and 8 Gbps
extension blades, but doing so defeats the concept of a multiple circuit FCIP tunnel. Defining two
tunnels between a pair of switches or blades rather than one tunnel with two circuits is not as
redundant or fault tolerant as having one multiple circuit tunnel.
FCIP tunnel restrictions for FCP and FICON emulation features
Multiple FCIP tunnels are not supported between pairs of 8 Gbps extension switches and 8 Gbps
extension blades when any of the FICON or FCP emulation features are enabled on the tunnel
unless TI Zones or LS/LF configurations are used to provide deterministic flows between the
switches. The emulation features require deterministic FC Frame routing between all initiators and
devices over multiple tunnels. If there are non-controlled parallel (equal cost) tunnels between the
same SID/DID pairs, emulation (Fast Write, Tape Pipelining, XRC or FICON Tape Pipelining) will fail
when a command is routed via tunnel 1 and the responses are returned via tunnel 2. Therefore
multiple equal cost tunnels are not supported between the switch pairs when emulation is enabled
on any one or more tunnels without controlling the routing of SID/DID pairs to individual tunnels
using TI Zones or LS/LF configurations.
WAN
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10.0.0.1
10.0.0.2
10.0.1.1
10.0.1.2
FCIP Circuits
10.0.0.3
10.0.1.3
10.0.0.4
10.0.1.4
10.0.0.5
10.0.1.5
FCIP Tunnel
FCIP Circuits