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When designing source-route bridging (SRB) internetworks featuring routers and IBM Systems Network Architecture (SNA) entities, you must carefully consider the configuration of SNA nodes as well as routing nodes. This appendix provides examples that focus on three specific SNA devices:
Figure C-1 illustrates a typical environment. Table C-1 through Table C-6 present the definition parameters for the devices shown in Figure C-1.
The parameters listed in Table C-1 through Table C-6 illustrate input to the Network Control Program (NCP) system generation process that runs in the host processor using the Network Definition Facility (NDF). The NDF is part of the ACF/NCP/System Support Program utility. The output produced by the generation process is a load module that runs in an FEP. Its typical size can be slightly under one MB to more than three MB. The ACF/NCP/System Support Program utility is also used for loading and dumping an FEP.
The following tables outline relevant parameters for generating Token Ring resources.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
1.5 | Local ring acknowledgment timer (seconds). | |
2.5 | Remote ring acknowledgment timer (seconds). | |
5000 | Maximum amount of sessions for all attached resources. | |
None | Maximum number of NTRI physical connections (Version 5.2.1 and earlier only). | |
None | Maximum number of NTRI logical connections (Version 5.2.1 and earlier only). | |
(localt2, remott2, N3) | (Version 5.R4 and later only.) Parameters specify a receiver acknowledgement/timer(T2) for local and remote Token Rings whether from peripheral or subarea nodes. Acceptable values: localt2 range is 0 to 2.0 seconds; remott2 range is 0 to 2.0 seconds; N3 range is 1 to 127 (default is 2). The values for localt2 and remott2 should be 10.0 percent of the value of the adjacent stations's T1 timer. N3 specifies the maximum number of I-frames received without sending an acknowledgment for subarea connections. |
The LUDRPOOL definition shown in Table C-2 specifies the number of peripheral resources required for the correct amount of control block storage to be reserved for new connections.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
None | Maximum is 16,000. | |
None | Required for LU Type 2.1 devices (independent LUs). |
The GROUP definition shown in Table C-3 specifies group definition parameters.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
Number | Specifies the number of LINE/PU pairs for this group. | |
Y | Twin FEP backup capable resource. | |
Y | ||
Y | TIC capable of IPL loading FEP. | |
YES or NO | Applies to ECLTYPE parameter specifications. YES required for (LOGICAL,PERIPHERAL); NO required for all other combinations indicated in ECLTYPE specification. | |
(PHYSICAL,ANY) (PHYSICAL, (PHYSICAL, (LOGICAL, (LOGICAL, | Allows PU 4 and PU 2 devices to attach. Allows PU 2 devices only. Allows PU 4 devices only. Defines devices attaching as PU 2. Defines devices attaching as PU 4. | |
SDLC | Required for NCP processing compatibility. | |
None | Required for ECLTYPE LOGICAL only; links this to a ECLTYPE PHYSICAL. | |
error, ras, stap, or lstap | Entry points for NTRI timer routines. |
The LINE definition shown in Table C-4 specifies line definition parameters.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
TIC1 TIC2 | 4-MB Token Ring interface 4- or 16-MB Token Ring interface | |
1088 to1095 | Range of valid addresses for TICs; only one specified per LINE definition | |
52 | Time in seconds the ring can beacon before TIC considers it down; maximum is 600 | |
4000abbbbbbb | Locally administered TIC address, where a is any value from 0 to 7; and b is any integer value from 0 to 9 | |
1.5 | V5R4; same as in BUILD, but only for PU 4 (LOGICAL, SUBAREA) devices; allows granularity for individual TICs for SUBAREA connections | |
2.5 | V5R4 parameter; same as LOCALTO; see BUILD parameters in Table C-1 | |
localt2, remott2, N3 | V5.4 parameter; see BUILD parameters in Table C-1; can be defined in LINE definition only if a subarea node was defined in GROUP definition | |
2044 to 16732 | Specifies maximum data in bytes that NTRI can transmit; TIC1 maximum is 2044; TIC2 maximum at TRSPEED16 is 16732 | |
Number | For association of physical to logical ECLTYPEs; matches physical or logical ECLTYPE specification | |
m, t, n, ml | Where m = number of retries for remote ring sessions, t = pause between retry sequence, n = number of retry sequences, and ml = number of retries in a sequence for local ring sessions | |
4 or 16 | TIC speed |
Table C-5 specifies physical unit (PU) definition parameters.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
aa4000bccccccc | Destination service access point (DSAP) and MAC address for the PU of the Token Ring device in the FEP, where aa = the DSAP and is a nonzero hexadecimal multiple of 4; b = 0 to 7; | |
|
| c = 0 to 9; enter 4000 as shown; only specified if ECLTYPE defined in GROUP definition is one of the following: (LOG,SUB), (PHY,SUB), (PHY,ANY) |
1, 2, or 4 | Depends on ECLTYPE: ♦ For NTRI LOGICAL resources, only PUTYPE=2 is valid; for NTRI PHYSICAL resources, only PUTYPE=1 is valid ♦ For NTRI PHYSICAL/SUBAREA LINES and PHYSICAL PERIPHERAL LINES, only PUTYPE=1 is valid. For NTRI LOGICAL PERIPHERAL LINES, only PUTYPE=2 is valid | |
XID | Defines the capability of a PU to receive and respond to an XID while in normal disconnected mode; for NTRI LOGICAL LINES, only YES is valid; for NTRI PHYSICAL LINES, only NO is valid |
Table C-6 specifies logical unit (LU) definition parameters.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
0 |
Devices that are attached to Token Ring and communicate with an IBM host application must be defined via the VTAM access method associated with the host. These devices are seen as dial-in resources from the host side and are defined in a configuration component named Switched Major Node. Some common definitions used in network configurations are outlined in Table C-7 through Table C-9.
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
SWNET | Specifies a type of resource for VTAM; SWNET indicates switched major node type |
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
017 | Typical values:
| |
xxxxx | Unique number identifying a device | |
1 to 7 | Number of I-frames sent before acknowledgment is required | |
265 | Indicates maximum number of bytes a PU 2 device can receive; ignored for PU 2.1, as this value is negotiable Default for 3174 is 521 | |
2 | Only valid value | |
YES or NO | YES should be used for PU 2.1 devices NO should be specified for any other device |
Parameter | Example, Parameter Value, or Range | Parameter Description and Implementation Notes |
|---|---|---|
2 through FF |
The following configuration was taken from 3174-13R cluster controller serial number 45362 connected to a Token Ring. These entries were used with a specific 3174 running on a 4-Mbps Token Ring. The configuration of this 3174-13R involved three specific configuration screens. Table C-10 through Table C-12 list the configuration line numbers, entries used, and descriptions of the configuration line. When applicable, extended descriptions are included for configuration entries that are relevant to the requirements of the routed internetwork.
| Configuration Line Number | Sample Value | Parameter Description and Implementation Notes |
|---|---|---|
98 |
| Online test password |
99 | TKNRNG | Description field |
100 | 13R | Model number |
101 | 7 | Host attachment type |
| Configuration Line Number | Sample Value | Parameter Description and Implementation Notes |
|---|---|---|
106 | 4000 2222 4444 04 | The first 12 hexadecimal digits form the source MAC address of the cluster controller (4000 2222 4444); the last two digits are the source SAP (SSAP) for LLC2 (0x04 = SNA). |
107 | 4000 0037 4501 04 | The first 12 hexadecimal digits form the destination MAC address of the FEP (4000 0037 4501); the last two digits are the DSAP for LLC2 (0x04 for SNA). |
108 | 0045362 | Serial number of the cluster controller |
110 | 0 | MLT storage support |
116 | 0 | Individual port assignment |
121 | 01 | Keyboard language |
123 | 0 | Country extended code page support |
125 | 00000000 | Miscellaneous options (A) |
126 | 00000000 | Miscellaneous options (B) |
127 | 0 0 | RTM definition |
132 | 0000 | Alternate base keyboard selection |
136 | 0000 | Standard keyboard layout |
137 | 0000 | Modified keyboard layout |
138 | 0 | Standard keypad layout |
141 | A | Magnetic character set |
165 | 0 | Compressed program symbols |
166 | A | Attribute select keypad |
168 | 0 | Additional extension; mode key definition |
173 | 0000 | DFT options |
175 | 000000 | DFT password |
179 | 000 | Local format storage |
213 | 0 | Between bracket printer sharing |
215 | 45362 | PU identification |
222 | 0 | Support for command retry |
382 | 0521 | Maximum ring I-frame size; range of values is 265 to 2057. |
383 | 2 | Maximum number of I-frames 3174 will transmit before awaiting an acknowledgment (transmit window size). |
384 | 0 | Ring speed of the Token Ring network:
|
| Configuration Line Number | Sample Value | Parameter Description and Implementation Notes |
|---|---|---|
500 | 0 | CSCM unique |
501 | TOSFNID | Network identifier |
503 | TOSFCTLR | LU name |
SNA end stations implement Logical Link Control type 2 (LLC2) when attached to a local-area network (LAN). LLC2 implements the following:
Figure C-2Figure C-2 illustrates how the T1 reply timer and error recovery operates for a 3174. Assume that the link between the two routers just failed. The following sequence characterizes the error recovery process illustrated in Figure C-2:
1. The 3174 sends a data frame and starts its T1 timer.
2. The T1 timer expires after 1.6 seconds.
3. The 3174 goes into error recovery.
4. The 3174 sends an LLC request (a receiver ready with the poll bit on), which requests the 3745 to immediately acknowledge this frame.
5. The 3174 starts its T1 timer.
6. The T1 timer expires after 1.6 seconds.
This operation is retried a total of seven times. The total elapsed time to disconnect the session is calculated as follows:
Posted: Wed Apr 10 10:50:53 PDT 2002
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