HP Fabric OS 6.2.2f Release Notes (5697-1756, February 2012)

Extended Fabrics and R_RDY flow control
• Starting with Fabric OS 5.1, the Extended Fabrics feature is supported with R_RDY flow control
(R_RDY flow control mode can be enabled using the portCfgISLMode command). R_RDY
flow control mode that uses IDLE primitives does not support frame-based trunking for devices
such as Time Division Multiplexor (TDM). To overcome this limitation and provide support for
frame-based trunking with Extended Fabrics, Fabric OS 6.2.x has been enhanced to support
interoperability with these distance extension devices.
Fabric OS 6.2.x allows Extended Fabrics E_Ports to operate in VC_RDY mode using either
ARB or IDLE primitives as fill words. This allows frame-based trunking to be supported on
Extended Fabrics E_Ports even when IDLE primitives are configured for these ports when
operating in native VC_RDY mode. Prior to this change, frame-based trunking was supported
only when ARB primitives were used in VC_RDY mode. With Fabric OS 6.2.x, frame-based
Trunking is supported on Extended Fabrics E_Ports even if IDLE or ARB primitives are used
when operating in native VC_RDY mode.
Implementation
The portcfglongdistance CLI parameter VC Translation Link Init is now overloaded
to specify whether the long distance link should use IDLE or ARB primitives. By default vc_init is
enabled. When vc_init is enabled, the long distance link uses ARB primitives. When vc_init is
disabled, the link uses IDLE primitives.
The buffer-to-buffer credit recovery feature is not supported on Extended Fabrics E_Port when it is
configured to use IDLE primitives. The user must disable buffer-to-buffer credit recovery feature using
the command portcfgcreditrecovery and specifying the disable option; otherwise, the link
will continuously reset.
The Adaptive Networking SID/DID Traffic Prioritization QoS feature is not supported on Extended
Fabrics E_Ports when IDLE primitives are configured on these ports. In this mode only data virtual
channels are available when QoS related virtual channels are not available.
When connecting to an extension device that does not support ARB primitives (such as some TDM
products), the following configuration must be used:
• portcfgqos -disable <port>
• portcfgcreditrecovery –disable <port>
• portcfglongdistance <port><LD|LD>0<distance>
The fabric parameter fabric.ops.mode.longdistance is now deprecated and should not
be used.
8-Gb Link Init and fill words
This section describes the portCfgfillWord command.
Overview
The FC Physical Interfaces (FC-PI) standard defines the requirements for a physical layer. It considers
all aspects of transmit, receive, and cable-plant performance requirements for optical and electrical
links. The FC-PI standard has been modified to support new physical-layer variants that operate at
higher data rates than those specified in FC-PI-2. The standard enables interoperability of transmitter
devices, receiver devices, interconnects, and components from different manufacturers. New
variants include support for an 800 MB/s data rate. The previous implementation by Brocade was
to use IDLE for Link Init and as fill words, which works for 1-Gb, 2-Gb, 4-Gb, and most 8-Gb
devices. However, some of the new 8-Gb devices have problems with the IDLE/IDLE sequence at
8 Gb. 8-Gb switches, HBAs, and smaller mid-range 8-Gb storage devices are using the IDLE/IDLE
sequences without any problems. Some of the new 8-Gb devices require that the ARB (FF)/ARB
(FF) sequence have successful Link Initialization. Brocade has developed an implementation of ARB
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