Defining LLC2 Ports

From the SNA Service screen (Configure -> WAN/Data Services -> SNA), click on the LLC2 Ports link at the top of the screen. You will see the SNA LLC2 Ports screen listing the current LLC2 ports, like the following example:

Click on Modify next to the Port Index of the LLC2 port configuration you want to define. You will see the Modify an SNA LLC2 Port screen with the current port parameters, like the following example:

Parameter

Range of Values

Default Value

Required Action

Port Name

1 to 8 alphanumeric characters

none

Enter the name of this port. The name must contain only ASCII printable characters and must be unique for each LLC2 port.

ACK Timer

Integer (1..65535)

5000

Enter the maximum time, in milliseconds, that the LLC2 port should expect an acknowledgement to a transmitted I-frame.

ACK Delay Timer

Integer (0..65535)

300

This is the T2 default acknowledgement timer. Enter the maximum time in milliseconds to wait before sending an acknowledgement for a sequenced PDU. 0 means no delay for acknowledgement.

Rcv Window Size

Integer (0..127)

7

This is the default receive window size. Enter the maximum number of unacknowledged I-frames that may be received. 0 tells the Passport 4400 unit to use the value determined by the switching component.

Poll Bit Timer

Integer (0..65535)

5000

Enter the time in milliseconds to wait for a response to a frame sent with the poll bit set.

REJECT Frame Timer

Integer (0..65535)

5

Enter the time in seconds to wait for a response to a reject frame.

Busy Timer

Integer (0..65535)

5

Enter the time in seconds that the LLC2 port waits for an indication of clearance of a busy condition at the adjacent link station.

Inactivity Timer

Integer (0..65535)

30

Enter the time in seconds that a Receiver Ready keep alive frame is sent on an idle link.

XID Timer

Integer (0..65535)

6

Enter the time in seconds between XID retries.

XID Retries

Integer (0..65535)

10

The maximum number of XID retries. 65535 means the XID retries will continue indefinitely.

TEST Timer

Integer (0..65535)

6

Enter the interval in seconds between TEST retries.

TEST Retries

Integer (0..65535)

10

Enter the maximum number of TEST retries. 65535 means the TEST retries will continue indefinitely.

New Window ACKs

Integer (0..127)

4

Enter the number of I-frames that must be acknowledged before the dynamic window algorithm increments the current working window size.

Max. Tx Retries

Integer (0..65535)

5

Enter the maximum number of times an attempt is made to retransmit a response across the interface. This parameter affects ACK Timer, Poll Bit Timer, REJECT Frame Timer, and Busy Timer.

Local Ring Number

Integer (0..4095)

0

Enter the number of the ring (Token Ring) to which the Passport 4400 unit is connected. This will make the Passport 4400 SNA services interoperate with third party routers over RFC 1490.

Click on the Save button to save any changes you have made. Then, reset the unit. (Select Administration and System Reset from the navigation menu. Select Configuration as the Reset Type. Then, click on the Reset button.)

Parameter	Range of Values	Default Value	Required Action
Port Name	1 to 8 alphanumeric characters	none	Enter the name of this port. The name must contain only ASCII printable characters and must be unique for each LLC2 port.
ACK Timer	Integer (1..65535)	5000	Enter the maximum time, in milliseconds, that the LLC2 port should expect an acknowledgement to a transmitted I-frame.
ACK Delay Timer	Integer (0..65535)	300	This is the T2 default acknowledgement timer. Enter the maximum time in milliseconds to wait before sending an acknowledgement for a sequenced PDU. 0 means no delay for acknowledgement.
Rcv Window Size	Integer (0..127)	7	This is the default receive window size. Enter the maximum number of unacknowledged I-frames that may be received. 0 tells the Passport 4400 unit to use the value determined by the switching component.
Poll Bit Timer	Integer (0..65535)	5000	Enter the time in milliseconds to wait for a response to a frame sent with the poll bit set.
REJECT Frame Timer	Integer (0..65535)	5	Enter the time in seconds to wait for a response to a reject frame.
Busy Timer	Integer (0..65535)	5	Enter the time in seconds that the LLC2 port waits for an indication of clearance of a busy condition at the adjacent link station.
Inactivity Timer	Integer (0..65535)	30	Enter the time in seconds that a Receiver Ready keep alive frame is sent on an idle link.
XID Timer	Integer (0..65535)	6	Enter the time in seconds between XID retries.
XID Retries	Integer (0..65535)	10	The maximum number of XID retries. 65535 means the XID retries will continue indefinitely.
TEST Timer	Integer (0..65535)	6	Enter the interval in seconds between TEST retries.
TEST Retries	Integer (0..65535)	10	Enter the maximum number of TEST retries. 65535 means the TEST retries will continue indefinitely.
New Window ACKs	Integer (0..127)	4	Enter the number of I-frames that must be acknowledged before the dynamic window algorithm increments the current working window size.
Max. Tx Retries	Integer (0..65535)	5	Enter the maximum number of times an attempt is made to retransmit a response across the interface. This parameter affects ACK Timer, Poll Bit Timer, REJECT Frame Timer, and Busy Timer.
Local Ring Number	Integer (0..4095)	0	Enter the number of the ring (Token Ring) to which the Passport 4400 unit is connected. This will make the Passport 4400 SNA services interoperate with third party routers over RFC 1490.