McDATA® 4Gb SAN Switch for HP p-Class BladeSystem Installation Guide (AA-RW1XC-TE, November 2006)

20 Planning
Each switch has a zoning database that includes the active zone set, all zones, and all zone members.
Table 2 describes the zoning database limits.
Performance
The switch supports class 2 and class 3 Fibre Channel service with a maximum frame size of 2148 bytes at
transmission rates of 1-Gb/s, 2-Gb/s, or 4-Gb/s. An external port adapts its transmission speed to match
that of the device to which it is connected prior to login when the connected device powers up. Related
performance characteristics include the following:
• Distance, page 20
• Bandwidth, page 20
• Latency, page 21
Distance
Consider the physical distribution of devices and switches in the fabric. Choose SFP transceivers that are
compatible with the cable type, distance, Fibre Channel revision level, and the device. See ”Specifications”
on page 47 for more information about cable types and transceivers.
Each Fibre Channel port is supported by a data buffer with an 8-credit capacity; that is, 8 maximum-sized
frames. For fibre optic cables, this enables full bandwidth over the following approximate distances:
• 13 kilometers at 1-Gb/s (0.6 credits/Km)
• 6 kilometers at 2-Gb/s (1.2 credits/Km)
• 3 kilometers at 4-Gb/s (2.4 credits/km)
Beyond these distances, however, there is some loss of efficiency because the transmitting port must wait
for an R_RDY response before sending the next frame.
Bandwidth
Bandwidth is a measure of the volume of data that can be transmitted at a given transmission rate. An
Fibre Channel port can transmit or receive at nominal rates of 1-Gb/s, 2-Gb/s, or 4-Gb/s depending on
the device to which it is connected. This corresponds to full duplex bandwidth values of 212, 425, and
850 MB. Multiple source ports can transmit to the same destination port if the destination bandwidth is
greater than or equal to the combined source bandwidth. For example, two 1-Gb/s source ports can
transmit to one 2-Gb/s destination port. Similarly, one source port can feed multiple destination ports if the
combined destination bandwidth is greater than or equal to the source bandwidth.
In multiple switch fabrics, each link between switches contributes 212, 425, or 850 MB of bandwidth
between those switches depending on the speed of the link. When additional bandwidth is needed
between devices, increase the number of links between the connecting switches.
Table 2 Zoning limits
Limit Description
MaxZoneSets Maximum number of zone sets (1)
MaxZones Maximum number of zones (2047)
MaxTotalMembers Maximum number of zone members (10,000) that can be
stored in the switch’s zoning database
MaxZonesInZoneSets Maximum number of zones that are components of the
active zone set (2047), excluding the orphan zone set, that
can be stored in the switch’s zoning database
MaxMembersPerZone Maximum number of members in a zone (4096)