Diff-Serv Traffic Engineering
Page 116 7450 ESS MPLS Guide
interface level and the interface specific configured value overrides the global configured
value. The BC value can be changed at any time. The operator can specify the BC for a CT
which is not used in any of the TE class definition but that does not get used by any LSP
originating or transiting this node.
d. Configuration of the Admission Control Policy to be used: only the Maximum
Allocation Model (MAM) is supported. The MAM value represents the bandwidth
constraint models for the admission control of an LSP reservation to a link.
RSVP Interface Level
The following are the configuration steps at the RSVP interface level:
1. The operator configures the percentage of RSVP interface bandwidth each CT shares, for
example, the BC, using the class-type-bw command. The value entered at the interface
level overrides the global value configured under the diffserv-te node.
2. The operator can overbook (underbook) the maximum reservable bandwidth of a given
CT by overbooking (underbooking) the interface maximum reservable bandwidth via
configuring the appropriate value for the subscription percentage parameter in the
config>router>rsvp>interface context.
3. .Both the BC value and the subscription parameter can be changed at any time.
LSP and LSP Path Levels
The following are the configuration steps at the LSP and LSP path levels:
1. The operator configures the CT in which the LSP belongs by configuring the class-type
ct-number command at the LSP level and/or the path level. The path level value overrides
the LSP level value. By default, an LSP belongs to CT0.
2. Only one CT per LSP path is allowed per RFC 4124, Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering. A multi-class LSP path is achieved through
mapping multiple system Forwarding Classes to a CT.
3. The signaled CT of a dynamic bypass must always be CT0 regardless of the CT of the
primary LSP path. The setup and hold priorities must be set to default values, for example,
7 and 0 respectively. This assumes that the operator configured a couple of TE classes, one
which combines CT0 and a priority of 7 and the other which combines CTO and a priority
of 0. If not, the bypass LSP will not be signaled and will go into the down state.
4. The operator cannot configure the CT, setup priority, and holding priority of a manual
bypass. They are always signaled with CT0 and the default setup and holding priorities.
To Next Page
Loading...
