Configuration of IP communication channels for LMP and RSVP

Configuration starts with enabling the IP Communication Channel (IPCC) between the 7750 SR or 7950 XRS UNI-C and the adjacent UNI-N. The IPCC is a data communication channel for LMP and RSVP. For each different UNI-C and UNI-N adjacency, a different IPCC must be configured.

A numbered network IP interface is bound to the port connected to the DCN or directly to the 1830 PSS.

GMPLS protocols use a new loopback address type, called a GMPLS loopback, on the IPCC. The address of this loopback is termed the local GMPLS router ID. Packets that do not belong to a GMPLS protocol that are destined for this loopback address are dropped. An interface is configured as a GMPLS loopback using the interface interface-name gmpls-loopback command.

config
        — router
            — interface local-gmpls-router-id-name gmpls-loopback
                — address local-gmpls-loopback-address

The destination address of the LMP and RSVP control plane packets should be set to the LMP/GMPLS loopback of the 1830 PSS. The 1830 PSS does that via a dedicated subnet on a VLAN interface on the management port. Another VLAN extends a separate subnet for management purposes. On the 7750 SR or 7950 XRS, the LMP and RSVP control plane packets should be sent to the next-hop for the GMPLS/LMP loopback address of the neighboring 1830 PSS. The 1830 PSS and the GMPLS router IDs must be in the same subnet. It is possible to operate over a routed DCN if the RSVP control plane messages do not set the IP router alert bit. Otherwise only direct IP connectivity over a Layer 2 network works.

If the IPCC goes down, an existing TE Link or gLSP to a peer UNI-N node is not torn down just because the IPCC is down. However, if the IPCC is down, then it is not possible to establish new gLSPs or TE Links, and a trap indicating a degraded state is raised.

The IPCC can use GRE encapsulation. This may be required in some network deployments where a routed DCN is used and is shared between multiple applications, to conceal GMPLS control plane traffic.

GRE encapsulation requires that a controlTunnel loopback interface representing the GRE tunnel is configured using the interface interface-name control-tunnel command. One IP tunnel can then be created on this interface. The local end tunnel IP address is configured using the interface primary IP address. The remote end tunnel IP address can be configured using the ip-tunnel command. GRE encapsulation is used by default for the IP tunnel.

Only the primary IPv4 interface address and only one IP tunnel per interface are allowed. Up to four tunnels can be configured using multiple controlTunnel loopback interfaces.

A static route is required to take the new controlTunnel interface as a next hop.

Note: GRE may be configured for IPCCs using a network interface or CPM port.

The following example illustrates the commands required to enable GRE tunneling on IP control channels to a peer UNI-N.

In this example, an IPCC is established between the 7750 SR (10.20.40.40) and the 1830 PSS (10.20.50.50). Packets destined for 10.20.50.50 match a static route pointing to interface ‟myTunneltf1”, which is a controlTunnel loopback interface. When this interface is matched as a next hop, the system adds GRE encapsulation (in the CPM) to the packet and send it out using the source address 10.3.30.10 and destination address 10.3.30.1 for the tunnel (outer) IP header.

 configure router "Base"|<cpm-vr-name>          -> cpm-vr-name "management" not 
                                                   supported.
        interface "ipcc" gmpls-loopback
            address 10.20.40.40/32
        exit
        interface "myTunnelItf1" control-tunnel -> new ifType: controlTunnel(32)
            address 10.3.30.10/32               -> tunnel local address
            ip-tunnel
                remote-ip 10.3.30.1             -> tunnel remote address, gre encap 
                                                   implicit
                ...                             -> future commands may be added, 
                                                   e.g. encap (default will be gre)
            exit
            no shutdown                         -> interface is operationally up
                                                   only if remote-ip is reachable
        exit
        static-route-entry 10.20.50.50/32       -> static route pointing to 
                                                   IPCC remote
 end
            next-hop "myTunnelItf1"             -> interface of new controlTunnel
                                                   ifType can be configured as
                                                   next-hop
                no shutdown
            exit
        exit
        static-route-entry 10.3.30.1/32         -> eventually static route to reach
                                                   tunnel remote end may be needed
            next-hop 10.3.10.1
                no shutdown
            exit
        exit
    exit