Specifications

Wavelength Division Multiplexing
39Continuous Access and Data Replication Manager SAN Extensions Reference Guide
Qualified vendor products for WDM
HP supports the use of all WDM-enabled intersite Fibre Channel provided the
WDM equipment is configurable to 1- or 2-gigabits per second data rates. Both
CWDM and DWDM systems are supported. The switch vendors do not
recommend extending the fabric beyond 100 km because of a drop in
performance. HP recommends that you not exceed 200 km with a 1-Gb link, and
at these limits, to notify users that there will be a decrease in performance.
Note: HP supports up to 240 km across a WDM link at 1 Gbps Fibre Channel with
reduced performance levels. The performance levels attained are dependent on the
number of buffers available in the particular switch models used and the specific
application data transfer size. In configurations where the WDM link is 200 km, the
total device to device distance (sum of all segments) must not exceed 203 km for 1
Gbps Fibre Channel. 2Gbps WDM links are supported up to 100 km only. To see how
buffer-to-buffer throughput diminishes over distance, see Figure 14 on page 52.
HP support for all WDM products has been the result of extensive and successful
testing of many systems over a wide range of StorageWorks product versions.
Based on the experience gained during certification efforts, combined with the
maturity of current WDM technology, HP has high confidence in the
interoperability of current and future WDM products with HP storage products.
Figure 6 through Figure 8 show a comparison of configuration options for DRM
and Continuous Access EVA systems. See Continuous Access XP documentation
for configuration options.
Figure 6: Simple point-to-point configuration using one long-haul fiber link
FC Switch A
FC Switch B
FC Switch Y
FC Switch Z
CXO7205B
WDM WDM
Local site
Remote site
Link Redundancy:
non-existent
Cost: low
ISL failure risk: high