Addendum to NETBuilder 8.2 Release Notes--SDLC

Modified: 02/11/96

Addendum to NETBuilder 8.2 Release Notes--SDLC

Introduction

This addendum to software version 8.2 NETBuilder® Family Bridge/Router Release Notes provides information regarding SDLC functionality.

If you have questions about the software, the manuals, or these release notes, contact 3Com® or your network supplier.

For information on the command syntax used in these release notes, refer to the About This Guide section of the NETBuilder Family Bridge/Router Operation Guide.

New Feature

This section describes the new feature added for SDLC versions of software.

SDLC support for DLSw

This release of software version 8.2 provides SDLC support for DLSw in NETBuilder II® software by converting all incoming SDLC protocols to LLC2. SDLC conversion is available for DLSw configuration across TCP/IP networks, for PU Type 2 devices such as 3270 terminal/cluster controllers. All SNA PU1, PU2, PU2.1 compliant nodes attached over SDLC or LLC2 are supported in software version 8.2. The SDLC support for DLSw allows aggregation of traffic from many SDLC-attached SNA devices over frame relay to a host-based FEP (using RFC 1490 encapsulation) so that a single frame relay line can replace multiple leased SDLC lines. To reduce the number of PVCs (DLCIs) required, all SLDC CUs will need to be defined with the same MAC address; use SAPs to differentiate the CUs.

On the NETBuilder II system,SDLC is supported only on the HSS 3-Port modules.

NETBuilder II Software Packages and Hardware Requirements

The NETBuilder II Bridge/Router supports five different software packages in software version 8.2. Table 1 outlines each software package and its hardware requirements. This section has been updated from the NETBuilder Family Bridge/Router Release Notes to reflect SDLC versions of software.

Table 1 NETBuilder II Software Packages
Software Package	Features	Minimum Hardware Required
(AP) APPN Multiprotocol** The AP package does not support the NETBuilder II multiprocessor (MP) 6-port Ethernet modules	Bridging, Boundary Routing, IP, IPX, LLC2, tunneling, DLSw, APPN, PPP, X.25, Frame Relay, and SDLC conversion	CEC 20 MB module For single-image support: 10 MB flash drive. Dual-image support: two 10 MB flash drives (requires the NETBuilder II 8-Slot Extended chassis).
(CP) Complete Protocols	Bridging, Boundary Routing, all routing, LLC2, tunneling, DLSw, PPP, and SDLC conversion	CEC 20 MB module For single- or dual-image support: one 10 MB flash drive.
(FF) Extended WAN	Bridging, Boundary Routing, all routing, LLC2, tunneling, DLSw, all WAN protocols, and SDLC conversion	CEC 20 MB module For single- or dual-image support: one 10 MB flash drive.

NETBuilder II Firmware Requirements

If you are using an HSS 3-Port module, you should upgrade the module to firmware version 1.1.5. Table 2 shows the required firmware.

Table 2 NETBuilder II Firmware Requirements
Module Software/Firmware	Required 8.2 Version
CEC Firmware	2.1
HSS 3-Port module Firmware	1.1.5.00 or higher

Notes and Cautions

This section describes notes, cautions, and other considerations to be aware of when using the SDLC version of NETBuilder 8.2 software.

SDLC Notes

The following information pertains to SDLC configurations:

Checking Status of CUs

To display the current status of defined CUs, enter the following command:

SHow [!<CU name>] -SDLC CUStat

To display statistics for CUs, enter the following command:

SHOw [!<CU name>] -SDLC CUInfo

Defining PCs as Type 2.0 Nodes

Some PC communication products (such as IBM® Communications Manager) always use T2.1 XID negotiation. To use these systems as T2.0 devices (for example, 3270 emulation) you must turn on XID spoofing on the NETBuilder system using the following commands:

SETDefault !<CU Name> -SDLC CUXId = <value> (8 Hexadecimal digits)
SETDefault !<CU Name> -SDLC CUXidDefined = Yes

Firmware Requirements

SDLC requires HSS 3-Port module firmware version 1.1.5.00 or later.

Improving SDLC performance on Multi-drop Lines

Use physical full duplex mode on multi-drop lines to improve performance. To set full duplex, enter the following command:

SETDefault !<path> -PATH DUplex = Full

For performance reasons, 3Com recommends using physical full duplex whenever possible. Use half duplex only when necessary. To use physical half-duplex for SDLC, the -PATH TxIdle and -PATH DUplex parameters need to be configured as follows:

SETDefault !<path> -PATH DUplex = Half
SETDefault !<path> -PATH TxIdle = Mark

Station Timeout

If a station is responding to polls from the NETBuilder system but does not acknowledge transmitted data (for example, the station sends RR frames without updating the N(R) value), the NETBuilder system will retransmit the data up to five times. If five retransmissions in a row are not acknowledged, the system will consider the secondary inoperable and bring the connection down. (On a multidrop link, the connections to other active stations should be unaffected.)

If the station indicates its unwillingness to receive data by using RNR frames, the NETBuilder system will never time it out; a station may remain busy indefinitely.

Known Problems

This section describes known problems in the SDLC version of NETBuilder 8.2 software.

SDLC and FRMR Frames

The NETBuilder system ignores frame reject (FRMR) frames when it is polling with XID frames; the downstream PU can remain in FRMR state with the NETBuilder polling indefinitely. Depending on the type of physical connection and the particular type of PU, disabling the port or path, disconnecting the SDLC cable from the PU, or power cycling the PU may be required to recover. If the CUXidDefined parameter is changed to Yes and the CUMOde parameter is set to Originate, the system will poll with an SNRM, which can be used to recover. 3Com recommends this configuration to avoid this problem.

SDLC Poll Addresses

The system will not prevent the same poll address from being assigned to multiple CUs on the same port. When configuring a primary multidrop port, make sure to configure a unique poll address for each CU; only one CU may use the C1 default setting.

SDLC Ports and Paths

The following notes apply to SDLC ports and paths:

n The SDLC path may stay up even when the attached device is turned off. To verify whether the path is up or down, enter the following syntax:

SHow [!<CU Name>] -SDLC CUStatus

n When the port owner is changed to SDLC, the port automatically comes up even if nothing is attached.

n If you disable the -SDLC PCONtrol parameter, the protocol will stop but the port or path will stay up, and the NETBuilder system will not drop DTR.

n If SDLC is enabled on a port or path which is down, SDLC will try to re-use the port every 30 seconds. As a result, when the port or path comes up, there may be up to a 30-second delay before the first SDLC frame appears on the line.

n Console messages stating that ports or paths are up or down do not apply to SDLC, except that the SDLC protocol cannot operate over a port which is down. There are no asynchronous console messages to indicate the SDLC protocol state for a port or station; you must display the appropriate SDLC parameters.

Limitations

This section describes limitations of the SDLC version of NETBuilder 8.2 software.

SDLC and Source Route Discovery

SDLC does not support Source Route Discovery. If you set Source Route Discovery to an SDLC port, you will not receive an error message.

SDLC Port Display

When you enter the SHow -SYS ADDress command, the address of SDLC ports will not be shown, even if the SDLC ports are up. To display the address, enter the SHow -SYS CONFiguration command.

© 3Com Corporation