Brocade Fabric OS FCIP Administrator's Guide v7.1.0 (53-1002748-01, March 2013)

Fabric OS FCIP Administrator’s Guide 17

53-1002748-01

FCIP Trunking

FIGURE 4 FCIP tunnel and FCIP circuits

Design for redundancy and fault tolerance

Multiple FCIP tunnels can be defined between pairs of 7800 switches or FX8-24 blades, but doing

so defeats the benefits of a multiple circuit FCIP tunnel. Defining two tunnels between a pair of

switches or blades is not as redundant or fault tolerant as having multiple circuits in one tunnel.

FCIP Trunking provides Lossless Link Loss (LLL). LLL ensures all data lost in flight is retransmitted

and placed back in order prior to being delivered to upper layer protocols. This is an essential

feature to prevent interface control checks (IFCC) on mainframes using FICON and SCSI time-outs

for open-system-based replication.

FCIP tunnel restrictions for FCP and FICON acceleration features

Multiple FCIP tunnels are not supported between pairs of 7800 switches or FX8-24 blades when

any of the FICON emulation or acceleration features or FCP acceleration features are enabled on

the tunnel, unless TI Zones or LS/LF configurations are used to provide deterministic flows

between the switches. These features require deterministic FC frame routing between all initiators

and devices over multiple tunnels. Non-controlled, parallel (equal cost multi-path) 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 Virtual Fabric

(VF) LS/LF configurations.

Note these additional restrictions:

• FICON networks with FCIP emulating and nonemulating tunnels do not support Exchange

Based Routing (EBR) configurations.

• If one end of a FICON emulating tunnel runs Fabric OS v7.0.0 or later, both ends of the tunnel

must run Fabric OS v7.0.0 or later.

• When planning Fabric OS upgrades or downgrades, it is recommended that you upgrade or

downgrade both end points of the FCIP tunnel (FICON or FCP) concurrently with the same

Fabric OS version if either the FICON or FCP emulation features is active. This is because

limited interoperability testing is performed in FICON or FCP emulation configurations between

FOS releases.

FCIP Circuits

IP Router

10.0.0.1

IP Router

10.0.1.1

10.0.0.2

10.0.0.3

10.0.0.4

10.0.0.5

FCIP Circuits

FCIP Tunnel

WAN

10.0.1.2

10.0.1.3

10.0.1.4

10.0.1.5