RUSIZES


>>-+---------------------+-------------------------------------><
   '-RUSIZES--=--ru_size-'

macroinstructions:

MODEENT

range:

see formula

Specifies a portion of the transmission services usage field (bytes 9 and 10 in the session parameter field) for this logon mode. It specifies the maximum length in bytes of the RUs that the primary logical unit and secondary logical unit can send to each other, as calculated by the formula m x 2ⁿ.

Specify RUSIZES as four hexadecimal digits. The leftmost two digits apply to the secondary logical unit, and the rightmost two digits apply to the primary logical unit.

The format is the same for both sets of digits. The first digit is the mantissa (m), and it must be in the range X'8'–X'F'. The second digit is the exponent (n), and it must be in the range X'0'–X'F'.

For example, RUSIZES=X'96A8' specifies that the secondary logical unit can send a maximum length of 9 x 2⁶ (or 576) bytes and that the primary logical unit can send a maximum of 10 x 2⁸ (or 2560) bytes.

Table 1 shows the exponents, mantissas, and the values for RUSIZES.

Note: For non-APPC sessions, if both the mantissa and exponent are set to 0 or if RUSIZES is not specified, then the default size is used. The default is obtained as follows:

If the BIND is an extended BIND, the default is X'FFFF'.
If the BIND is not an extended BIND, the default is the value of the MAXLURU start option.

For APPC sessions, if the RU size value is zero or less than 256, the value is overridden and set to 256.

Table 1. Exponent and mantissa values for each RU size
Exp (n)	Mantissa (m)
	8	9	A	B	C	D	E	F
0	8	9	10	11	12	13	14	15
1	16	18	20	22	24	26	28	30
2	32	36	40	44	48	52	56	60
3	64	72	80	88	96	104	112	120
4	128	144	160	176	192	208	224	240
5	256	288	320	352	384	416	448	480
6	512	576	640	704	768	832	896	960
7	1024	1152	1280	1408	1536	1664	1792	1920
8	2048	2304	2560	2816	3072	3328	3584	3840
9	4096	4608	5120	5632	6144	6656	7168	7680
A	8192	9216	10240	11264	12288	13312	14336	15360
B	16384	18432	20480	22528	24576	26624	28672	30720
C	32768	36864	40960	45056	49152	53248	57344	61440
D	65536	73728	81920	90112	98304	106496	114688	122880
E	131072	147456	163840	180224	196608	212992	229376	245760
F	262144	294912	327680	360448	393216	425984	458752	491520