Limitations 47

 

NetBIOS sessions occurs if the primary link fails and the redundant link is activated.

 

If this happens, end users need to log on and initiate another session.

Maximum BSC Line

For V.35 and RS-232 links, the maximum baud rate supported for BSC traffic is

Speed

38.4. If the baud rate is higher, BSC traffic suffers errors and retransmissions.

Multilink PPP

Multilink PPP (MLP) is supported for multiple WAN links connected to the same

Configurations

port running PPP.

When configuring MLP:

For maximum performance on a NETBuilder II bridge/router, 3Com recommends that similar hardware interface types be configured for each MLP bundle. For instance, bundle HSS modules with HSS modules, and bundle HSS 3-port module links with HSS 3-port module links.

For the best performance, use MLP on interfaces with matched line speeds. Avoid mismatched baud rates of ratios greater than 10 to 1 for bundled links.

If your baud rate ratios on two links are greater than 4 to 1, the MLP feature automatically turns off fragmentation. For baud ratios of less than 4 to 1, you may choose to turn off fragmentation for performance considerations. Turn off fragmentation using the MlpCONTrol parameter in the PPP Service.

MLP does not support the HSSI module.

Before you re-enable a port running MLP, disable the port and allow the remote port to go down. This action prevents loss of packet sequence numbers synchronization, which causes packets to be dropped when the MLP port is enabled.

Multiport MBRI Module The Multiport MBRI module cannot be configured using SNMP.

SNMP Management

NAT Proxy ARP NAT does not support proxy ARP. If the NETBuilder bridge/router is configured for NAT private address space, you should use a different network address on the RHS other than the directly connected network IP address. Additionally, you should specify a static route to that address on the remote host.

RouteDiscovery If RouteDiscovery is enabled on all protocols (-SR RouteDiscovery = All), in the maximum packet forwarding rate drops significantly during route discovery. 3Com recommends that you enable RouteDiscovery only for the protocols you use. Increasing the value of the -SR HoldTime parameter minimizes the drop in forwarding rate for these protocols.

SDHLC Half-DuplexSDHLC does not support physical half-duplex mode.

Mode

SDLC SDLC requires the following:

XID spoofing must be turned on if the IBM Communication Manager is used for 3270 communications and is defined as a PU type 2.0. Use the following syntax:

SETDefault !<PU name> -SDLC CUXId = <value> (8 Hexadecimal digits)

SETDefault !<PU name> -SDLC CUXidDefined = Yes

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3Com 11.1 manual Speed, Multilink PPP, Port running PPP, Snmp Management, Mode