Technical data
DATA CENTER TECHNICAL BRIEF
Operational Simplicity: Automating and Simplifying SAN Provisioning 5 of 15
Test Benet
Link
Performance
Generates trafc patterns similar to the projected trafc patterns over links of the new fabric
to ensure that it meets performance requirements and detects potential congestion points
Transceiver
Health Check
Validates that all electrical and optical components of the transceiver are working as
designed and that the decibel budget between the links is within tolerance
Transceiver
Uptime
Proactively monitors and trends for the integrity of the optics during its operational life cycle,
with the power on hours or years
This testing and analysis is enabled through a new port operational mode called the ClearLink diagnostics port,
or “ClearLink D_Port.” Part of Brocade Fabric Vision technology, Brocade ClearLink Diagnostics is a patent-
pending technology that is used to simplify and automate SAN physical layer diagnostics.
The ClearLink D_Port is statically congured by the user to run diagnostics during pre-deployment or when there
are susceptible physical layer issues. It is an ofine diagnostics tool that allows users to automate a battery
of tests to measure and validate latency and distance across the switch links, as well as to verify the integrity
of 16 Gbps transceivers in the fabric. In addition, a ClearLink D_Port requires only the individual ports that are
attached to the link being tested to go ofine, leaving the rest of the ports to operate online, in isolation from
the link being tested.
In addition to switch-to-switch link validation, Brocade FOS v7.1 provides dynamic ClearLink D_Port support
between Gen 5 Fibre Channel switches and Brocade 1860 Fabric Adapters when running at 16 Gbps speed.
Brocade FOS v7.1 also provides ClearLink D_Port support for Gen 5 Fibre Channel switches running in Access
Gateway mode, as well as for UltraScale Inter-Chassis Links (ICLs) on Brocade DCX® 8510 Backbones. (Note:
ClearLink D_Port on UltraScale ICLs skips the electrical and optical loopback tests, as the Quad Small Form-
Factor Pluggable [QSFP] used does not support it.)
How Does ClearLink D_Port Work?
Brocade Network Advisor or Brocade FOS Command-Line Interface (CLI) commands can be used to initiate the
ClearLink diagnostic tests to validate the cables and transceivers.
Figure 2 is an example of two Gen 5 Fibre Channel switches that are connected via Inter-Switch Links (ISLs),
either local or over distance. When the ports are set in the ClearLink D_Port mode, the tests are automatically
initiated on both ends of the link. In this mode, it is possible to validate:
•The electrical components of the local transceiver
•The optical and electrical components of the remote transceiver
•The link distance (in meters) and latency (in nanoseconds) between the ports