EXP Computer S200 manual Local Termination spoofs, Local Termination does not spoof

LLC2 Local Termination

Spoofing	Local termination or “spoofing” of LLC protocol means that acknowledgments to
	information frames and certain supervisory frames are handled locally by the
	spoofer. The spoofer, the LT software in a PathBuilder S200 series switch, ensures
	the acknowledged information frames are reliably delivered to the destination peer
	spoofer and that any flow control issues are handled appropriately. Because of local
	acknowledgment, spoofing of LLC frames may enhance network performance and
	allows for reliable Token Ring to Token Ring connectivity.
	This table describes the types of frames Local Termination spoofs:
	Local Termination spoofs:
	All Specifically Routed LLC frames, such as I frames and Supervisory frames
	Local Termination does not spoof:
	• Route Explorer frames, such as ARE or STE
	• Internally matched frames coming in from the LAN port
	• Frames generated by LSS/LLC in the bridge going out to the LAN port
	• WAN to WAN frames
Maximum Sessions
	The maximum number of sessions you can spoof at one time is 64. If you reach the
Spoofed	maximum number of sessions, Local Termination does not establish additional
	spoofing sessions, nor does it source route bridge the additional sessions.
What Happens
	Local Termination runs a subset of LLC2 protocol between spoofers to ensure that
between Spoofers	frame traffic reliably passes from one edge point node to another edge point node in
	your network. The subset protocol uses separate timers and retry counts that can be
	set greater than the LLC protocol timers.
Intermediate
	LLC2 LT supports intermediate Token Ring networks between spoofers. For
Frames between	example, Figure 53 shows Local Termination running in the edge point nodes of this
Spoofers	network to provide “spoofing” across multiple Token Rings.
	Spoofing
	Intermediate Ring

FEP

#1

PB	X.25
LT

PB

BN

PB

BN

PB LT

FEP	End
#2	Station

LT enabled with MAC Address of FEP #1 and SAP value being used.

LT enabled with MAC Address of FEP #2 and SAP value being used.

Figure 53. Example of LT Spoofing

104 Bridging