Alcatel-Lucent 7750 SR OS Service Manual page 382

Configuring a VPLS Service with CLI
The default value of
limited by the standard STP parameter interaction formulae.
CLI Syntax: config>service>vpls service-id# stp
Forward Delay
RSTP, as defined in the IEEE 802.1D-2004 standards, will normally transition to the forwarding
state via a handshaking mechanism (rapid transition), without any waiting times. If handshaking
fails (e.g. on shared links, see below), the system falls back to the timer-based mechanism defined
in the original STP (802.1D-1998) standard.
A shared link is a link with more than two Ethernet bridges (for example, a shared 10/100BaseT
segment). The
section
For timer-based transitions, the 802.1D-2004 standard defines an internal variable forward-delay,
which is used in calculating the default number of seconds that a SAP or spoke SDP spends in the
discarding and learning states when transitioning to the forwarding state.
The value of the forward-delay variable depends on the STP operating mode of the VPLS
instance:
•
•
CLI Syntax: config>service>vpls service-id# stp
Page 382
max-age
max-age max-info-age
Range:
6 to 40 seconds
Default:
20 seconds
Restore Default: no max-age
command is used to configure a link as point-to-point or shared (see
port-type
SAP Link Type on page
in mode, but only when the SAP or spoke SDP has not fallen back to legacy STP
rstp
operation, the value configured by the
in all other situations, the value configured by the
forward-delay seconds
Range:
4 to 30 seconds
Default:
15 seconds
Restore Default: no forward-delay
is 20. This parameter can be modified within a range of 6 to 40,
392).
hello-time
7750 SR OS Services Guide
command is used;
command is used.
forward-delay