Class of Service (COS) Definitions
COS entries are defined in the CONFIG DD statement in the same library that defines the node entries.
In the Platform Server COS definitions, you can define the following functions:
- The buffer sizes that are passed between the Platform Server and VTAM/TCP.
- The time of day that transfers can be run.
- For TCP requests, you can throttle transfer of data to or from a node. In other words, you can set a maximum number of bytes per second that can be sent to or received from a node.
Note: This is only useful for TCP transfers because SNA already has a Class of Service feature that you can use to prioritize data traffic.
COS entries can be enabled at startup if they are contained in the node startup list. Additionally, they can be enabled through the
ENABLE
operator command and disabled through the
DISABLE
operator command.
If a COS entry is defined for a file transfer, and the COS entry is not disabled, the transfer can run as if no COS entry is defined.
9
when running early in the morning. If the transfer runs long enough, the priority might be changed to another value based on the parameters in the COS entry.
Additional node parameters are required to perform TCP throttling of data sent and received. For more information, see BPS_INIT
, BPS_RECEV
, BPS_RESP
, BPS_SEND
, BPS_TOTAL
, DEFAULT_COSNAME
.
The COS definitions can be divided to two sections. The first section describes the required parameters and the parameters that define the buffer sizes that are passed between the Platform Server and TCP/VTAM.
See the following table for the parameters in the first section:
Parameter | Description |
---|---|
TYPE
|
Distinguishes between NODE entries and COS entries.
This is a required parameter. You must set the value as
|
SBUFSIZE
|
Defines the buffers size in bytes that the Platform Server uses when sending data to VTAM or TCP.
This is an optional parameter. Valid values are from
By specifying a larger value, you save CPU cycles at the cost of using more storage. You might want to specify a value lower than
|
RBUFSIZE
|
Defines the buffers size in bytes that the Platform Server uses when receiving data from VTAM or TCP.
This is an optional parameter. Valid values are from
By specifying a larger value, you save CPU cycles at the cost of using more storage. You might want to specify a value lower than
|
The second section describes the parameters that define the time period when a file transfer can run, and throttle the transfer of data to and from TCP. These parameters must be on the same line in the documented order. You must define all of the parameters.
You can define up to nine lines of the following parameters for a single COS definition. If you attempt to have more than nine entries, an error message is displayed and the COS definition is not enabled. If you do not want to use some of the parameters, you can use the default values as shown in the following sample:
DAYS=YYYYYYY,STIME=0000,ETIME=2400,PRIORITY=9
This field is broken into four parameters. The first three parameters
DAYS
,
STIME
and
ETIME
are filter parameters, while the fourth parameter
PRIORITY
defines the priority that is used when the current time passes the filters.
See the following table for the descriptions of the four parameters:
Parameter | Description |
---|---|
DAYS | Defines the days of the week.
This parameter must have 7 digits that are either
When specified as
|
STIME | Defines the start time to check.
It is defined in military time from
|
ETIME | Defines the end time to check.
It is defined in military time from
|
PRIORITY | Defines the priority associated with a file transfer if the current day and time passes all the filter parameters:
DAYS ,
STIME and
ETIME .
Valid values are the following 10 priorities:
|
See the following copy of the
COSDFLT
entry that is provided in the Platform Server
SAMPLIB
library:
*********************************************************************** * SAMPLE COS (CLASS OF SERVICE) ENTRY: COSDFLT ************************************************************************ TYPE=COS Defines that this is a COS entry SBUFSIZE=32000 Sets the TCP SEND Buffer Size RBUFSIZE=32000 Sets the TCP RECEIVE Buffer Size *********************************************************************** * Parameters that limit file transfer speed * * Up to 9 lines can be defined per class of service * * Parameters must be on the same line in the defined order: * * DAYS=xxxxxxxx (Y or N) Days of the week starting with Sunday * * STIME=xxxx (hhmm) Start time (0000-2359) * * ETIME=xxxx (hhmm) End time (0000-2359) * * PRIORITY=x (0-9) Priority ************************************************************************ * The following line sets high priority 7 days a week 24 hours/day DAYS=YNNNNNY,STIME=0000,ETIME=2359,PRIORITY=9 High priority 7x24 * The following lines sets high priority all day Sunday/Saturday * They are currently commented out *DAYS=YNNNNNY,STIME=0000,ETIME=2359,PRIORITY=9 High Sun/Sat 7x24 * The following lines sets different priorities for Monday-Friday DAYS=NYYYYYN,STIME=0000,ETIME=0700,PRIORITY=9 High Mid-7AM DAYS=NYYYYYN,STIME=0700,ETIME=0900,PRIORITY=5 Medium 7-9AM DAYS=NYYYYYN,STIME=0900,ETIME=1700,PRIORITY=0 Do not Run 9-5pm DAYS=NYYYYYN,STIME=1700,ETIME=1900,PRIORITY=5 Medium 5-7pm DAYS=NYYYYYN,STIME=1900,ETIME=2359,PRIORITY=9 High 7-12mid
This COS definition sets the send and receive buffer sizes to 32000. The priority is set to
9
(high) for all transfers running on Saturday and Sunday. The last five lines set different priorities for transfers running on Monday through Friday.
- For transfers running between midnight and 7 a.m., the priority is set to
9
. - For transfers running between 7 a.m. and 9 a.m., the priority is set to
5
. - For transfers running between 9 a.m. and 5 p.m., the priority is set to
0
. - For transfers running between 5 p.m. and 7 p.m., the priority is set to
5
. - For transfers running between 7 p.m. and midnight, the priority is set to
9
.