Chapter 4. IBM iSeries 270 models 103
LAN and WAN adapters
Comm.
Restrictions
Restrictions apply when using specific adapters and I/O processors. Basic communications restrictions when using the
MFIOP, #2629, #2699, #2720, #2721, #2745, #2809, #2824, and other communications functions are identified here. This
information is a brief summary.
Maximum protocol speeds on the EIA-232/ITU V.24 electrical interfaces:
– 64 Kbps for Synchronous PPP, BSC, SDLC, and X.25
– 115.2 Kbps for Asynchronous protocols (including Asynchronous PPP)
Maximum protocol speeds on the ITU V.35:
Permitted only on 20-ft (6.2 m) cable
– 2.048 Mbps for Synchronous PPP, SDLC, and frame relay
– 230.4 Kbps for Asynchronous PPP
– 640 Kbps for X.25
– 64 Kbps for BSC
Speeds faster than 512 Kbps might require either the looped or inverted clocking to be configured.
Maximum protocol speeds on the EIA-449/ITU V.36:
– 2.048 Mbps for Synchronous PPP, SDLC, and frame relay
– 230.4 Kbps for Asynchronous PPP
– 640 Kbps for X.25
– 64 Kbps for BSC
“Looped” clocking is required on cables longer than 20 ft (6 m).
Speeds faster than 512 Kbps might require either the looped or inverted clocking to be configured.
Maximum protocol speeds on the ITU X.21 electrical interfaces:
Permitted only on 20-ft (6.2 m) cable
– 2.048 Mbps for Synchronous PPP, SDLC, and frame relay
– 640 Kbps for X.25
Speeds faster than 512 Kbps might require either the looped or inverted clocking to be configured.
Only one Frame Relay or one X.25 communication line is allowed per IOP.
One high-speed line is permitted per IOP.
ASYNC and ASYNC PPP above 115.2 Kbps is a high-speed line.
Frame relay, SDLC, SYNC PPP, and X.25 above 64 Kbps is a high-speed line.
High-speed lines are supported on ITU X.21, ITU V.35 20-ft (6 m) cables, or EIA-449/ITU V.36 electrical
interfaces.
No high-speed communication line is allowed when a #2750, #2751, or #2761 is installed under the same I/O
processor.
If it is desired to run multiple emulated LAN lines on an #281x ATM IOA, then the following restrictions must be
satisfied:
– The 281x ATM IOA must be running under a dedicated #2824 PCI Feature Controller (no other IOAs of any type).
– The number of emulated LANs running on the #281x ATM IOA is limited to a maximum of two, one token ring and
one Ethernet.
Frame relay restrictions:
– Minimum line speed 56 Kbps
– Frame relay is not allowed on EIA-232/V.24 electrical interface
Other IOAs allowed under same #2809 PCI LAN/WAN/Workstation IOP or #2824 PCI Feature Controller, one of two
restrictions:
– Either a #281x or #2838
– A #2718 or #2729 and maximum of one #2721, #2722, #2723, #2724, #2729, #2745, or #2746
IPX is supported on frame relay, LAN, and ATM.
– IPX is supported only on OS/400 V5R1 and earlier, not on OS/400 V5R2.
– Devices running IPX over the Integrated xSeries Server is limited to 2400 routes and 2400 services.
– Devices running IPX are limited to 1400 routes and 1400 services when:
• #2723, #2724, or #2838 IOAs are not controlled by the Integrated xSeries Server.
• Frame relay running over a #2721, #2745, or #2699 IOA.
SDLC restrictions:
– Maximum of 64 remote locations per #2809, #2824, or #2629 IOP.
X.25 restrictions:
– Limit of 16 virtual circuits (16 remote locations).
– Limit of 64 virtual circuits (64 remote locations) in the #5065 Storage/PCI Expansion Tower.
– Speeds faster than 512 Kbps might require either looped or inverted clocking to be configured.
– The other port of the #2721 or #2745 can be used as a low-speed communications line.
