Installation guide

8-7
Device Manager Guide, Cisco ACE 4700 Series Application Control Engine Appliance
OL-26645-01
Chapter 8 Configuring Parameter Maps
Configuring Connection Parameter Maps
TCP Buffer Share
(Bytes)
To improve throughput and overall performance, the ACE buffers the number of bytes you specify
before processing received data or transmitting data. Use this option to increase the default buffer
size and thereby realize improved network performance.
Enter the maximum size of the TCP buffer in bytes. Valid entries are integers from 8192 to 262143
bytes. Default is 32768.
Note If you enter a value in this field for an ACE device that does not support this option, an error
message appears. Leave this field blank when creating or modifying a connection parameter
map for devices that do not support this option.
TCP Buffer Threshold
(%)
Select the TCP buffer threshold, expressed as a percent, to indicate when the TCP connection is to
be reset. This entry represents the maximum number of TCP connections that the hosts can open. This
entry prevents the ACE from exhausting all available buffers due to the outage caused by DDoS
attack.
The options are 50, 75, 77, 88, 95, and 100. The default value is 100.
Smallest TCP MSS
(Bytes)
Enter the size of the smallest segment of TCP data that the ACE is to accept. Valid entries are integers
from 0 to 65535 bytes. The value 0 indicates that the ACE is not to set a minimum limit.
Largest TCP MSS
(Bytes)
Enter the size of the largest segment of TCP data that the ACE is to accept. Valid entries are integers
from 0 to 65535 bytes. The value 0 indicates that the ACE is not to set a maximum limit.
SYN Retries Enter the number of attempts that the ACE is to make to transmit a TCP segment when initiating a
Layer 7 connection. Valid entries are integers from 1 to 15 with a default of 4.
TCP WAN
Optimization RTT
This option specifies how the ACE is to apply TCP optimizations to packets on a connection
associated with a Layer 7 policy map using a round-trip time (RTT) value:
• An entry of 0 (zero) indicates that the ACE is to apply TCP optimizations to packets for the life
of a connection.
• An entry of 65535 (the default) indicates that the ACE is to perform normal operations (that is,
without optimizations) for the life of a connection.
• Entries from 1 to 65534 indicate that the ACE is to use the following guidelines:
– If the actual client RTT is less than the configured RTT, the ACE performs normal operations
for the life of the connection.
– If the actual client RTT is greater than or equal to the configured RTT, the ACE performs
TCP optimizations on the packets for the life of a connection.
Valid entries are integers from 0 to 65535.
Timeout For
Embryonic
Connections
(Seconds)
An embryonic connection is a TCP three-way handshake for a connection that does not complete for
some reason.
Enter the number of seconds that the ACE is to wait before timing out an embryonic connection.
Valid entries are integers from 0 to 4294967295 with a default of 5. A value of 0 indicates that the
ACE is never to time out an embryonic connection.
Half Closed Timeout
(Seconds)
A half-closed connection is one in which the client or server sends a FIN and the server or client
acknowledges the FIN without sending a FIN itself.
Enter the number of seconds the ACE is to wait before closing a half-closed connection. Valid entries
are integers from 0 to 4294967295 with a default of 3600 (1 hour). A value of 0 indicates that the
ACE is never to time out a half-closed connection.
Table 8-3 Connection Parameter Map Attributes (continued)
Field Description