Policy-Based Tunnel Selection - Cisco ASR 9000 Series Configuration Manual

Policy-Based Tunnel Selection

Policy-Based Tunnel Selection
These topics provide information about policy-based tunnel selection (PBTS):
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Policy-Based Tunnel Selection
Policy-Based Tunnel Selection (PBTS) provides a mechanism that lets you direct traffic into specific TE
tunnels based on different criteria. PBTS will benefit Internet service providers (ISPs) who carry voice and
data traffic through their MPLS and MPLS/VPN networks, who want to route this traffic to provide optimized
voice service.
PBTS works by selecting tunnels based on the classification criteria of the incoming packets, which are based
on the IP precedence, experimental (EXP), differentiated services code point (DSCP), or type of service (ToS)
field in the packet. Default-class configured for paths is always zero (0). If there is no TE for a given
forward-class, then the default-class (0) will be tried. If there is no default-class, then the packet is
dropped.PBTS supports up to seven (exp 1 - 7) EXP values associated with a single TE tunnel.
This figure illustrates a PBTS implementation.
Figure 15: Policy-Based Tunnel Selection Implementation
Related Topics
Configuring Policy-based Tunnel Selection, on page 198
Policy-Based Tunnel Selection Functions
The following PBTS functions are supported on the Cisco ASR 9000 series router:
• Classify the IPv4 packets based on 5-Tuple values (source IP, destination IP, source port, destination
Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide, Release 4.3.x
132
Policy-Based Tunnel Selection, on page 132
Policy-Based Tunnel Selection Functions, on page 132
PBTS Forward Class, on page 133
PBTS Restrictions, on page 134
port, and protocol) specified via ACL.
Implementing MPLS Traffic Engineering
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