TE Class Mapping
Each of the eight available bandwidth values advertised in the IGP corresponds to a TE class. Because the
IGP advertises only eight bandwidth values, there can be a maximum of only eight TE classes supported in
an IETF DS-TE network.
TE class mapping must be exactly the same on all routers in a DS-TE domain. It is the responsibility of the
operator configure these settings properly as there is no way to automatically check or enforce consistency.
The operator must configure TE tunnel class types and priority levels to form a valid TE class. When the TE
class map configuration is changed, tunnels already up are brought down. Tunnels in the down state, can be
set up if a valid TE class map is found.
The default TE class and attributes are listed. The default mapping includes four class types.
Table 5: TE Classes and Priority
Priority
Class Type
TE Class
7
0
0
7
1
1
—
Unused
2
—
Unused
3
0
0
4
0
1
5
—
Unused
6
—
Unused
7
Flooding
Available bandwidth in all configured bandwidth pools is flooded on the network to calculate accurate constraint
paths when a new TE tunnel is configured. Flooding uses IGP protocol extensions and mechanisms to determine
when to flood the network with bandwidth.
Flooding Triggers
TE Link Management (TE-Link) notifies IGP for both global pool and sub-pool available bandwidth and
maximum bandwidth to flood the network in these events:
•
Periodic timer expires (this does not depend on bandwidth pool type).
•
Tunnel origination node has out-of-date information for either available global pool or sub-pool bandwidth,
causing tunnel admission failure at the midpoint.
Cisco IOS XR MPLS Configuration Guide for the Cisco CRS Router, Release 5.1.x
174
Implementing MPLS Traffic Engineering
Flooding