The Cambridge Backbone Ring

A Distributed Scheduling Algorithm for Real-Time Communication on Slotted Shared Medium

“…In order to achieve this, we consider a system where multiple streams are incident on various stations (or nodes) and the stations are interconnected over a ring architecture. We choose the ring architecture since it is a popular shared medium topology used in practice, for example FDDI [16,8], Cambridge slotted-ring networks [25,24,6,3,28,26], Orwell ring [27], and SCI ring [7,4,14,13]. Moreover, several other popular nonring-based protocols (e.g., DQDB and Token Bus [22]) can be logically mapped to a ring architecture [17], and a minor variation of the allocation and access mechanism could be applied there as well.…”

The hyper-ring network

“…Among the prominent ring networks are the token ring [13], Cambridge Backbone Ring (CBR) [4], HANGMAN [61, and the Distributed Queue Dual Bus (DQDB aka IEEE 802.6) [5], some of which are compatible with ATM rmission to make digital/hard copy of all or part of this work lbr personal or ssroom use is granted without li~e provided that copies are not made or tributed lbr profit or commercial advantage, the copyright notice, the title of the ~|ication and its date appear, and notice is given that copying is by permission of 'M, Inc. To cop} otherwise, to republish, to post on servers or to redistribute to s, requires prior specific permission and/or a lee. while others are not.…”

“…For instance, in Fig. 3, the 4 HR2's of the HR3 (6,4,4) are labeled O, !, 2, and 3 in a clockwise increasing fashion. The HR 1 rings in the bottom left HR 2 (labeled 3) are labeled 30, 31, 32, and 33 in an clockwise increasing fashion.…”

“…Higher dimensioned HWs can be recursively built in this fashion.Fig. 3depicts the HR3(6,4,4). The gateway nodes of the HR3(6 , 4, 4) to dimension 5 are nodes 021 and 024.…”

The Cambridge backbone network an overview and preliminary performance

“…The CBN architecture can be characterized in general terms as follows: Backbone network 500 to 1500 Mbit/sec slotted ring topology, ATM and multicast modes of operation, 200 km of bre { metropolitan dimensions, 30 km link length easily supported, Expected con guration typically 30 stations o ering 30 Mbit/sec each, Direct compatibility with Cambridge Fast Ring 4]. The CBN o ers an ATM LAN/Man architecture based around a source release slotted ring 1,4]. The network operates on monomode optical bre and is currently designed for an eventual line rate of 1000 Mbit/sec.…”