HP Surestore 64 FW 05.01.00 and SW 07.01.00 HP StorageWorks SAN High Availabil - Page 81

Distance requirements, Bandwidth, increased by using a variety of local area network LAN, metropolitan

Page 81 highlights

Planning Considerations for Fibre Channel Topologies ■ Distance requirements - The distance between elements in a fabric affects the type of optical port transceiver and cabling required. In addition, variables such as the number of connections, grade of fiber-optic cable, device restrictions, application restrictions, buffer-to-buffer credit limits, and performance requirements can affect distance requirements. Consider the following: - If the distance between two fabric elements is less than 250 meters (at 2.125 Gbps), any port type (shortwave or longwave laser) and any fiber-optic cable type (multimode or single-mode) can be used to create an ISL connection. In this case, cost or port availability may be the determining factor. - If the distance between two fabric elements exceeds 300 meters (at 2.125 Gbps), only longwave laser ports and single-mode fiber-optic cable can be used to create an ISL. - Distance limitations can be increased by using multiple fabric elements. Each director or switch retransmits received signals, thus performing a repeater and multiplexer function. Distance limitations can also be increased by using a variety of local area network (LAN), metropolitan area network (MAN) or wide area network (WAN) extension technologies. Note: Variables such as the number of connections, grade of fiber-optic cable, device restrictions, application restrictions, buffer-to-buffer credit limits, and performance requirements can affect distance requirements. ■ Bandwidth - ISL connections can be used to increase the total bandwidth available for data transfer between two directors or switches in a fabric. Increasing the number of ISLs between elements increases the corresponding total ISL bandwidth, but decreases the number of port connections available to devices. Table 2 illustrates ISL transfer rate versus port availability for a fabric consisting of two Director 2/64s. SAN High Availability Planning Guide 81

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174

Planning Considerations for Fibre Channel Topologies
81
SAN High Availability Planning Guide
Distance requirements
The distance between elements in a fabric affects
the type of optical port transceiver and cabling required. In addition, variables
such as the number of connections, grade of fiber-optic cable, device
restrictions, application restrictions, buffer-to-buffer credit limits, and
performance requirements can affect distance requirements. Consider the
following:
If the distance between two fabric elements is less than 250 meters (at
2.125 Gbps), any port type (shortwave or longwave laser) and any
fiber-optic cable type (multimode or single-mode) can be used to create
an ISL connection. In this case, cost or port availability may be the
determining factor.
If the distance between two fabric elements exceeds 300 meters (at 2.125
Gbps), only longwave laser ports and single-mode fiber-optic cable can be
used to create an ISL.
Distance limitations can be increased by using multiple fabric elements.
Each director or switch retransmits received signals, thus performing a
repeater and multiplexer function. Distance limitations can also be
increased by using a variety of local area network (LAN), metropolitan
area network (MAN) or wide area network (WAN) extension
technologies.
Note:
Variables such as the number of connections, grade of fiber-optic cable, device
restrictions, application restrictions, buffer-to-buffer credit limits, and performance
requirements can affect distance requirements.
Bandwidth —
ISL connections can be used to increase the total bandwidth
available for data transfer between two directors or switches in a fabric.
Increasing the number of ISLs between elements increases the corresponding
total ISL bandwidth, but decreases the number of port connections available
to devices.
Table 2
illustrates ISL transfer rate versus port availability for a
fabric consisting of two Director 2/64s.