McDATA Eclipse 2640 SAN, Administration And Configuration Manual

Page: 85 / 276

4
Configuring iSAN Connections
4-7
Configuring TCP Ports for iFCP
Manual Reset:
You may not want the auto-reset option to be on
when you are troubleshooting unrecoverable errors. In this
case, you can do a manual reset by clicking
Reset Port
in the
FC/Ethernet Port Configuration
dialog box.
2. Set the
MTU size
.
The MTU (maximum transmission unit) size can be used to
prevent accidental fragmentation when the path (discovered)
MTU value, as returned by paths from/to this port, is incorrect.
This can occur with some security/encryption appliances on the
network, where the MTU size may not be correctly reported. The
following options are available:
•
Auto
- Use the discovered MTU size. This is the default setting.
•
Manual
- Forces the system to use the configured value for
MTU size and DOES NOT do auto-discovery. The range is
from 512 to 4096, the default size is 1500.
•
Min
(Auto, Manual) - Does auto -discovery and uses the
minimum of the discovered and configured values.
Storage-optimized TCP Parameters:
Storage-optimized TCP is a set of enhancements made to the TCP
behavior to ensure high throughput in a dedicated network in
enterprise environments typically used for storage traffic. These
enhancements are built on the inherent reliability of TCP by
optimizing the traffic control features in a dedicated network.
Following are the TCP feature enhancements that make up the
storage-optimized TCP:
• Reorder resistance in case of out-of-order packet delivery.
• Quick start with higher initial value of congestion window.
• Smaller reduction in congestion window on slow start and fast
retransmit.
• Disabling congestion avoidance phase in fast retransmit and
fast recovery.
• Reduced slow start timeout.
You can implement these enhancements by selecting the checkboxes
provided in the
Advanced TCP Configuration
on page 4-6.