Ip-Over-Clns Tunnels; Table 9-13 Osi Virtual Router Constraints - Cisco ONS 15600 Reference Manual

Chapter 9 Management Network Connectivity
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•
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OSI virtual router constraints depend on the routing mode provisioned for the node.
the number of IS L1s, IS L1/L2s, and DCCs that are supported by each router. An IS L1 and IS L1/L2
support one ES per DCC subnet and up to 100 ESs per LAN subnet.
Table 9-13
Routing Mode
IS L1
IS L1/L2
Each OSI virtual router has a primary manual area address. You can also create two additional manual
area addresses. These manual area addresses can be used to:
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•
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9.6.8 IP-over-CLNS Tunnels

IP-over-CLNS tunnels are used to encapsulate IP for transport across OSI NEs. The ONS 15600 SDH
supports two tunnel types:
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•
Figure 9-25
C, and D). The tunnel ends are configured on NEs A and D, which support both IP and OSI. NEs B and
C only support OSI, so they only route the OSI packets.
78-18400-01
FT-TD
T-TD
LAN subnet
OSI Virtual Router Constraints
Router 1 Routers 2–12
Yes Yes
Yes Yes
Split up an area—Nodes within a given area can accumulate to a point that they are difficult to
manage, cause excessive traffic, or threaten to exceed the usable address space for an area.
Additional manual area addresses can be assigned so that you can smoothly partition a network into
separate areas without disrupting service.
Merge areas—Use transitional area addresses to merge as many as three separate areas into a single
area that shares a common area address.
Change to a different address—You might need to change an area address for a particular group of
nodes. Use multiple manual area addresses to allow incoming traffic intended for an old area address
to continue being routed to associated nodes.
GRE—Generic Routing Encapsulation is a tunneling protocol that encapsulates one network layer
for transport across another. GRE tunnels add both a CLNS header and a GRE header to the tunnel
frames. GRE tunnels are supported by Cisco routers and some other vendor NEs.
Cisco IP—The Cisco IP tunnel directly encapsulates the IP packet with no intermediate header.
Cisco IP is supported by most Cisco routers.
shows the protocol flow when an IP-over-CLNS tunnel is created through four NEs (A, B,
IS L1 IS L1/L2
per Area per Area
250 —
250 50
Cisco ONS 15600 SDH Reference Manual, Release 9.0
9.6.8 IP-over-CLNS Tunnels
Table 9-13 shows
DCC
per IS
60
60
9-37