Configuring TCP Data Retransmission

TCP is considered reliable in part because it requires that entities receiving data must acknowledge transmitted segments. If data segments go unacknowledged, then they are retransmitted until they are finally acknowledged or until the maximum number of retries has been reached. You can control both the number of times the Oracle® Enterprise Session Border Controller tries to retransmit unacknowledged segments and the periodic interval (how often) at which retransmissions occur.

You set two new options in the network parameters configuration to specify how many retransmissions are allowed and for how long: atcp-rxmt-interval and atcp-rxmt-count.

To configure TCP data retransmission:

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal

2. Type system and press Enter.

   ORACLE(configure)# system
   ORACLE(system)#

3. Type network-parameters and press Enter.

   ORACLE(system)# network-parameters
   ORACLE(network-parameters)#

4. options—Set the options parameter by typing options, a Space, the option name atcp-rxmt-interval=x (where x is a value in seconds between 2 and 60) with a plus sign in front of it. Then press Enter. This value will be used as the interval between retransmission of TCP data segments that have not been acknowledged.

   Now enter a second option to set the number of times the Oracle® Enterprise Session Border Controller will retransmit a data segment before it declares the connection failed. Set the options parameter by typing options, a Space, the option name atcp-rxmt-count=x (where x is a value between 4 and 12 representing how many retransmissions you want to enable) with a plus sign in front of it. Then press Enter.

   ORACLE(network-parameters)# options +atcp-rxmt-interval=30
   ORACLE(network-parameters)# options +atcp-rxmt-count=6

   If you type the option without the plus sign, you will overwrite any previously configured options. In order to append the new options to the configuration’s options list, you must prepend the new option with a plus sign as shown in the previous example.

5. Save and activate your configuration.