Olicom CrossFire 8600, Руководство по эксплуатации, Страница: 36 / 250

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CrossFire 8600/8605 Token-Ring Switches v. 1.2, P/N: 710001641 Switch Theory of Operation
Multiple Bridging Modes
The CrossFire 8600 and the CrossFire 8605 each supports four different switching
modes to provide maximum flexibility in all installation environments. The
switching modes are Source Route Switching (SRS), Source Route Bridging
(SRB), Source Route Transparent (SRT) and SRT/SRB. The switch operates on
two levels (BRF and CRF) as outlined below.
Figure 6. Typical Configuration with Switches Using Multiple Bridging Modes
The switch bridging modes are founded on the concept of Logical Rings. This
Logical Ring concept is equivalent to the DTR (IEEE 802.5r) standard’s
Concentrator Relay Function (CRF).
Each port on the switch belongs to a Logical Ring (CRF), which is a logical
grouping of ports within the switch. A Logical Ring can consist of any number of
ports within a switch or a switch stack. The ports within a Logical Ring do not have
to be adjacent.
The Logical Rings are assigned a ring number when the switch performs source
routing functions. The bridging is performed through the logical entity of the
Bridge Relay Function (BRF).
The Logical Ring (LR) communicates via a logical, virtual port with the Bridge
Relay Function, which functions as a multiport (virtual) bridge between the Logical
Rings. The switch can support up to 63 logical rings.