Riverstone Networks WICT1-12 - Manual (Page 628)

30-24 Riverstone Networks RS Switch Router User Guide Release 8.0
Inverse Multiplexer Overview WAN Configuration
30.14 INVERSE MULTIPLEXER OVERVIEW
The Inverse Multiplexer (IMUX) feature allows the Riverstone RS Switch Router to inter-operate with those Cabletron
Systems products that only support the WAN IMUX (Wide Area Networking Inverse Multiplexer) feature.
The RS Switch Router already implements a method of WAN link aggregation using Multilink PPP (MPPP) as detailed
in RFC1990. The IMUX functionality is added as an extension to the MPPP functionality.
Note For bandwidth aggregation between multiple RS Switch Routers, and other
vendors’ products, the non-proprietary Multilink PPP feature should be used.
The IMUX link state protocol provides a simple mechanism to detect when a WAN link has failed and quickly removes
the link from an IMUX group so that minimal disturbance to the flow of data occurs. The protocol also allows
additional WAN links to be added dynamically to an IMUX group, to allow a greater aggregation of WAN bandwidth.
An IMUX group cannot be configured across multiple modules. For example, an IMUX group can consist of four T1
lines, which must all be on the same Multi-Rate WAN Module (that is, t1.2.1-4). Also, the MP bundle being configured
for IMUX mode must first be configured to use bridged format encapsulation, using the
ppp set
ppp-encaps-bgd
command.
The following configuration shows how to configure IMUX using the four T1 ports in slot 2:
To check which ports have IMUX enabled (in this example, ports se.4.2 and se.4.3 are IMUX ports):
30.14.1 Bit Error Rate Testing an IMUX Group
Bit Error Rate Testing (BERT) can only be performed on a single physical or logical port. To perform a BERT test on
a port in an IMUX group, the port must first be removed from the group.
rs(config)# port set t1.2.1-4:1 timeslots 1-24 wan-encapsulation ppp
rs(config)# ppp create-mlp mp.1 slot 2
rs(config)# ppp add-to-mlp mp.1 port t1.2.1-4:1
rs(config)# ppp set ppp-encaps-bgd ports mp.1
rs(config)# ppp set mlp-imux-mode ports mp.1
rs# ppp show stats ports all-ports summary
Link IP IPX Bridge Encr Comp Imux
Adm/Opr Adm/Opr Adm/Opr Adm/Opr Adm/Opr Adm/Opr Adm/Opr
Port States States States States States States States
---- --/-- --/-- --/-- --/-- --/-- --/-- --/--
se.4.2 (mp.1) Up/Dn Up/Dn Up/Dn Up/Dn Dn/Dn Dn/Dn Up/Dn
se.4.3 (mp.1) Up/Dn Up/Dn Up/Dn Up/Dn Dn/Dn Dn/Dn Up/Dn
se.4.4 Up/Dn Up/Dn Up/Dn Up/Dn Dn/Dn Dn/Dn Dn/Dn
mp.1 Up/Dn Up/Dn Up/Dn Up/Dn Dn/Dn Dn/Dn Up/Dn
(L) denotes compression/encryption on an individual link
(M) denotes compression/encryption on the MLP bundle