Cisco Systems 15310-MA manual Static Category IP-Over-CLNS TL1 Tunnel Comments

Chapter 4 Cisco Transport Controller Operation

Using the CTC Launcher Application to Manage Multiple ONS Nodes

Figure 4-8 TL1 Tunnels

IP + OSI

Tunnel provisioning

IP DCN

CTC

Central office

Other vendor

GNE 1

TL1 tunnel

ONS ENE 1

OSI/DCC IP/DCC

IP

TL1 tunnel

Other vendor	ONS ENE 2
GNE 2
OSI/DCC	IP/DCC

140175

TL1 tunnels provide several advantages over static IP-over-CLNS tunnels. Because tunnel provisioning is needed only at the CTC computer, they are faster to set up. Because they use TL1 for TCP transport, they are more secure. TL1 tunnels also provide better flow control. On the other hand, IP over CLNS tunnels require less overhead and usually provide a slight performance edge over TL1 Tunnels (depending on network conditions). TL1 tunnels do not support all IP applications such as SNMP and RADIUS Authentication. Table 4-11shows a comparison between the two types of tunnels.

Table 4-11			TL1 and Static IP-Over-CLNS Tunnels Comparison
				Static
	Category			IP-Over-CLNS	TL1 Tunnel	Comments
	Setup			Complex	Simple	Requires provisioning at ONS NE, GNE, and DCN routers. For
						TL1 tunnels, provisioning is needed at CTC computer.
	Performance			Best	Average to	Static tunnels generally provide better performance than TL1
					good	tunnels, depending on TL1 encoding used. LV+Binary provides
						the best performance. Other encoding will produce slightly
						slower TL1 tunnel performance.
	Support all IP			Yes	No	TL1 tunnels do not support SNMP or RADIUS Server IP
	applications					applications.
	ITU Standard			Yes	No	Only the static IP-over-CLNS tunnels meet ITU standards. TL1
						tunnels are new.
	Tunnel traffic control			Good	Very good	Both tunnel types provide good traffic control
	Security setup			Complex	No setup	Static IP-over-CLNS tunnels require careful planning. Because
					needed	TL1 tunnels are carried by TL1, no security provisioning is
						needed.
		Cisco ONS 15310-MA SDH Reference Manual, Release 9.1 and Release 9.2
	4-18					78-19417-01