Use the DEVICE statement to specify the name and hexadecimal device number of the channel-to-channel (CTC) devices that you use. Use the LINK statement to define a network interface link associated with the CTC devices.
Requirement: You must use a separate DEVICE statement for each device you use. The same is true for the LINK statement.
For more information about missing interrupt handler (MIH) considerations with TCP/IP devices, see Missing interrupt handler factors.
Syntax
Rule: Specify the parameters in the order shown here.
>>-DEVice--device_name--CTC--base_device_number-----------------> .-IOBUFFERSIZE 32768---------. .-NOAUTORestart-. >--+----------------------------+--+---------------+----------->< '-IOBUFFERSIZE - buffer_size-' '-AUTORestart---'
Parameters
- device_name
- The name of the device. The maximum length is 16 characters. The same name is specified in the LINK statement.
- CTC
- Specifies the device is a channel-to-channel (CTC) device.
- base_device_number
- The hexadecimal base device number associated with the CTC adapter. Two numbers are used by TCP/IP: the base_device_number and base_device_number+1.
- IOBUFFERSIZE buffer_size
- Specifies the I/O buffer size. The buffer size must be 32K (minimum), 32 768 (default), or 65 535 (maximum).
- AUTORESTART | NOAUTORESTART
- Controls device failure reactivation behavior.
- NOAUTORESTART
- For most device failures, specifying NOAUTORESTART indicates that the TCP/IP address space does not attempt to reactivate this device.
- AUTORESTART
- In the event of a device failure, the TCP/IP address space attempts to reactivate the device. For more information, see Recovering from device failures.
Syntax
Rule: The optional parameters on the LINK statement following the device_name parameter can be specified in any order.
Parameters
- link_name
- The name of the link. The maximum length is 16 characters.
- CTC
- Specifies that the link is a channel-to-channel link.
- adapter_addr
- An integer used to specify whether the DEVICE statement's parameter, base_device_number, is the read device number or the write device number. Use 0 to indicate that the base device number is the read device and 1 to indicate that the base_device_number is the write device.
- device_name
- The device_name must be the same as specified in the DEVICE statement.
- IFSPEED ifspeed
- An optional estimate of the interface's current bandwidth in bits per second. The minimum value that can be specified for ifspeed for a CTC link is 0; the maximum value is 2 147 483 647. The default is 4 500 000. This value is accessible to SNMP for management queries, but has no effect on operation of the device.
- IFHSPEED ifhspeed
- An optional estimate of the interface's current bandwidth in one million bits per second units. The minimum value that can be specified for ifhspeed for a CTC link is 0; the maximum value is 2147. The default is 4. This value is accessible to SNMP for management queries, but has no effect on operation of the device.
- SECCLASS security_class
- Use this parameter to associate a security class for IP filtering
with this interface. In order for traffic over the interface to match
a filter rule, the filter rule must have the same security class value
as the interface or a value of 0. Filter rules can be specified in
the TCP/IP profile or in an IP Security policy file read by the Policy
Agent. Filter rules can include a security class specification on
the IpService statement in an IP Security policy file or on the SECCLASS
parameter on the IPSEC statement in the TCP/IP profile.
Valid security classes are identified as a number in the range 1 - 255. The default value is 255. For more information about security class values, see z/OS Communications Server: IP Configuration Guide.
Restriction: The TCP/IP stack ignores this value if IPSECURITY is not specified on the IPCONFIG statement.
- MONSYSPLEX | NOMONSYSPLEX
- Specifies whether or not sysplex autonomics should monitor the
link's status.
- NOMONSYSPLEX
- Specifies that sysplex autonomics should not monitor the link's status. This is the default value.
- MONSYSPLEX
- Specifies that sysplex autonomics should monitor the link's status.
Restriction: The MONSYSPLEX attribute is not in effect unless the MONINTERFACE keyword is specified on the GLOBALCONFIG SYSPLEXMONITOR profile statement. The presence of dynamic routes over this link is monitored if the DYNROUTE keyword is also specified on the GLOBALCONFIG SYSPLEXMONITOR profile statement.
Steps for modifying
See Modifying DEVICE and LINK statements for modifying information.
Usage notes
The configured I/O buffer sizes at each end of the CTC connection must match. A buffer size mismatch can cause packet loss or I/O errors, resulting in deactivation of the CTC connection. CTC I/O buffer size can be explicitly specified with the IOBUFFERSIZE parameter.