| Dynamic
Synchronous Transfer Mode |
For
the purposes of the present document, the following terms and definitions apply: Access
token:- right to use a slot for transmitting data on a physical interface for
a certain number of bypass hops Address, DTM address:- 64 bit numerical value
that uniquely identifies a node in a DTM network Allocation domain:- same as
a bypass chain where, if the topology is point-to-point or bus, the last node
is not counted as member of the AD. Bypass
Chain (BC):- series of concatenated physical links, where data can be transported
end-to-end using bypass switching.
Bypass
switching:- space switching of slots from a receiver to a transmitter on the same
physical interface on a per slot basis.The DTM Resource Management Protocol (DRMP)
handles control of transmission resources over bypass chains.
Resource
Management handles the right to use a time slot for transmission and the right
to administer usage rights. The latter function is referred to as slot ownership.
A physical interface owns a set of time slots on the bypass chain. The owner of
a time slot has the right to use it for transmission, but can also lend the right
to another physical interface if it is in greater need. Ownership can either be
statically configured on a bypass chain, or dynamic. In the latter case, the Dynamic
Ownership part of DRMP, distributes ownership along the physical interfaces on
the bypass chain according to a configured policy. Typically the physical interfaces
are configured to own an equal share that exhausts the capacity of the bypass
chain.The right to transmit on a time slot can be limited spatially, so as to
cover only as many physical links as is needed on a bypass chain for the intended
transmission. On the next physical link downstream of the receiver, and the next
physical link upstream of the transmitter, the same time slot can be used again
for other data transmissions. This spatial reuse of time slots is referred to
as slot scoping.
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