H3C Technologies H3C S6800 Series Switches - Manual (Page 93)

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Bandwidth
required by
primary
CRLSP
Primary CRLSP
requires
bandwidth
protection or not
Bypass tunnel providing
bandwidth protection
Bypass tunnel providing no
bandwidth protection
Non-zero No
The primary CRLSP can be bound
to the bypass tunnel when all the
following conditions are met:
• The bandwidth that the bypass
tunnel can protect is no less
than the bandwidth required
by the primary CRLSP.
• No CT that the bypass tunnel
can protect is specified, or the
specified CT is the same as
that of the traffic on the
primary CRLSP.
After binding, the RRO message
carries the bandwidth protection
flag.
This bypass tunnel is selected only
when no bypass tunnel that does
not provide bandwidth protection
can be bound to the primary
CRLSP.
The primary CRLSP can be bound to
the bypass tunnel when one of the
following conditions is met:
• No CT is specified for the bypass
tunnel.
• The specified CT is the same as
that of the traffic on the primary
CRLSP.
After binding, the RRO message
does not carry the bandwidth
protection flag.
The primary CRLSP prefers bypass
tunnels that does not provide
bandwidth protection over those
providing bandwidth protection.
Configuration restrictions and guidelines
When you configure a bypass tunnel on the PLR, follow these restrictions and guidelines:
• Use bypass tunnels to protect only critical interfaces or links when bandwidth is insufficient. Bypass
tunnels are pre-established and require extra bandwidth.
• Make sure the bandwidth assigned to the bypass tunnel is no less than the total bandwidth needed
by all primary CRLSPs to be protected by the bypass tunnel. Otherwise, some primary CRLSPs might
not be protected by the bypass tunnel.
• A bypass tunnel typically does not forward data when the primary CRLSP operates correctly. For a
bypass tunnel to also forward data during tunnel protection, you must assign adequate bandwidth
to the bypass tunnel.
• A bypass tunnel cannot be used for services such as VPN.
• You cannot configure FRR for a bypass tunnel. A bypass tunnel cannot act as a primary CRLSP.
• Make sure the protected node or interface is not on the bypass tunnel.
• After you associate a primary CRLSP that does not require bandwidth protection with a bypass
tunnel that provides bandwidth protection, the primary CRLSP occupies the bandwidth that the
bypass tunnel protects. The bandwidth is protected on a first-come-first-served basis. The primary
CRLSP that needs bandwidth protection cannot preempt the one that does not need bandwidth
protection.
• After an FRR, the primary CRLSP will be down if you modify the bandwidth that the bypass tunnel
can protect and your modification results in one of the following:
{
The CT type changes.
{
The bypass tunnel cannot protect adequate bandwidth as configured.