10-4
Catalyst 2950 Desktop Switch Software Configuration Guide
78-14982-01
Chapter 10 Configuring LRE
LRE Links and LRE Pr ofi les
Use the LL profiles (LRE-5LL, LRE-10LL, and LRE-15LL) with care. These profiles have the
low-latency (LL) feature enabled and the interleav er feature disabled. The LL feature does not delay
data transmission, but it makes data more susceptible to interruptions on the LRE link.
All other profiles, port and global, have the interleaver feature enabled and the LL feature disabled.
The interleaver feature provides maximum protection against small interruptions on the LRE link
but delays data transmission.
The sym metri c profiles (L RE-5, LR E-10, LR E-15, LRE -8, LRE -7, LRE -4, LRE-3 , and LRE -2)
provide full -duplex through put on the l ink betwee n the LRE s witch and CPE device . Under idea l
conditions, this can mean up to 30 Mbps of bandwidth on the LRE link if you are using the LRE-15
profile.

LRE Sequences

The LR E switch es a re shi pped wi th p redef i ne d sequ ence s. Sequ enc es are s ets of pro f iles and ar e us ed in
conjunctio n with the rate selection featu re. The rate selectio n featur e enables the switch to automati cally
select profiles. You can also define your own sets of sequence s using IOS comma nds or CMS. See the
Using Rate Selection to Automatically Assign Profiles section on page 10-10 for further information.
Table 10-2 outlines t he pre def ined seq uences for rate selection contain ed in Cisc o IOS. When ex ecuting
rate selection, the switch uses a sequences to choose an appropriate profile for a given LRE interface.
Table 10-2 LRE Rate Selection Sequences
LRE-SEQ-
COMPLETE-
REACH LRE-SEQ-
DOWNSTREAM LRE-SEQ-SYM LRE-SEQ-SYM-
LONGREACH LRE-SEQ-
SYMLL LRE-SEQ-
UPSTREAM
LRE-SEQ-
VIDEO-
TRANSMIT1
LRE-SEQ-
VIDEO-
TRANSMIT2
LRE-15 LRE-15 LRE-15 LRE-5 LRE-15LL LRE-15 LRE-15 LRE-15
LRE-10 LRE-15-5 LRE-10 LRE-4 LRE-10LL LRE-10 LRE-15-5 LRE-15-5
LRE-15-5 LRE-15-3 LRE-8 LRE-3 LRE-5LL LRE-8 LRE-15-3 LRE-10
LRE-10-5 LRE-15-1 LRE-7 LRE-2 LRE-7 LRE-15-1 LRE-10-5
LRE-8 LRE-10 LRE-5 LRE-4-1 LRE-15-5 LRE-10 LRE-15-3
LRE-7 LRE-10-5 LRE-4 LRE-10-5 LRE-10-5 LRE-10-3
LRE-15-3 LRE-10-3 LRE-3 LRE-5 LRE-10-3 LRE-15-1
LRE-10-3 LRE-10-1 LRE-2 LRE-4 LRE-10-1 LRE-10-1
LRE-5 LRE-8 LRE-15-3
LRE-15-1 LRE-7 LRE-10-3
LRE-10-1 LRE-5 LRE-3
LRE-4 LRE-4 LRE-2
LRE-3 LRE-4-1 LRE-4-1
LRE-2 LRE-3
LRE-4-1 LRE-2