3Com 11.1 manual Limitations

Limitations 45

Limitations	This section describes limitations of NETBuilder software version 11.1. Topics are in
	alphabetical order.
ACCM Not Configurable	The ACCM (Async Control Character Map) used for Async PPP cannot be
	configured. During LCP negotiation, the NETBuilder bridge/router always proposes
	an ACCM of all zeros and agrees to whatever the peer negotiates.
APPN	In software version 11.1, APPN does not support SMDS.
APPN DLUr Connections	When you configure an APPN dependent LU requestor (DLUr) connection from a
to 3174 Systems	NETBuilder II bridge/router to a 3174 cluster controller, the NETBuilder II network
	node and the 3174 must be on the same ring. In this configuration, the
	NETBuilder II token ring port must be set to transparent bridging only.
ATM Emulated LANs	The NETBuilder II bridge/router software supports a system maximum of 32 ATM
	emulated LANs.
Auto Start-up Does Not	Automatic detection of the line type (LineType=Auto) and link protocol
Include Async	(OWNer=Auto) do not include recognition of Async PPP and AT dial. For Async PPP
	and AT dial (which must be used together), the following parameters must be
	explicitly configured:
	-PATH LineType=Dialup
	-PATH DialMode=ATdial
	-PATH ExDevType=Async
	-PORT OWNer=PPP

BSC and Leased Lines

DLSw and IBM Boundary

Routing in Large

Networks

The PATH service parameter TransferMode should not be changed from its default value of AUto. Other settings of this parameter are reserved for future extensions.

The BSC pass-through feature is limited to leased lines and cannot use dialup links.

The following considerations are related to DLSw in large networks.

Leaf Node Sessions Support

When a leaf node has more than 50 end stations, use the following tuning parameters:

SETDefault !<port> -LLC2 TransmitWindow = 1

SETDefault !<port> -LLC2 RetryCount = 20

SETDefault !<port> -LLC2 TImerReply = 10000

Use these parameters for the leaf node and central node WAN ports.

Number of DLSw Circuits

The -SYS CONNectionUsage parameter controls the maximum number of DLSw circuits. The default value of the CONNectionUsage parameter is High for NETBuilder bridge/router with a DPE module and for the boundary router peripheral node, but the default value is low for all other NETBuilder bridge/router platforms. Change this value using:

SETDefault -SYS CONNectionUsage = Low Medium High

You must reboot the bridge/router before this change takes effect. Table 14 shows the maximum number of circuits possible with the different CONNectionUsage