cisco 	Shiva	Telebit		Xylogics	Xyplex

ARAP			y	y	y		y		y
PPP			y	y	y(1)		y		y
SLIP/CSLIP		y	y	y		y		y
Kerberos for above	n	n	n(2)		y(8)		y(3)
Access control			y	y		y(8)		(7)
Accounting			y			y(8)		y(5,7)
Protocol sensing			y(6)		n		n(7)
terminal-style login			y		y		y
SNMP management				y		y		y

NOTES:
1 - Never successfully demonstrated
2 - Only for C/SLIP and PPP
3 - For C/SLIP and PPP, only thru terminal login
4 - Thru scripting, not functional for ARAP (but I'm pushing)
5 - Not complete, again pushing
6 - Only between ARAP and terminal sessions
7 - Promised in next release
8 - Thru external server, sources provided