RSVP
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... IP over ATM. The general issues related
to running RSVP[4] over ATM have been covered in several papers
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... interoperability between different implementations. Requirements
for RSVP over ATM implementations are provided in [2].
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This section provides implementation guidelines for implementation of
RSVP over ATM. Several recommendations are common for all, RSVP
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... RSVP over ATM. Several recommendations are common for all, RSVP
sessions, both unicast and multicast ...
... RSVP Message VC Usage ...
...
The general issues related to which VC should be used for RSVP
messages is covered in [6]. It discussed several implementation
options including: mixed control and data, single control VC ...
... RSVP over ATM implementations SHOULD send RSVP control (messages)
over the best effort data path, see figure 1. It is permissible to
allow a user to override this behavior. The stated approach
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... VC requirements since the best effort data path will need
to exist in order for RSVP sessions to be established and in order
for RSVP ...
... RSVP sessions to be established and in order
for RSVP reservations to be initiated. The specific best effort
paths that will be used by RSVP are: for unicast ...
... for RSVP reservations to be initiated. The specific best effort
paths that will be used by RSVP are: for unicast, the same VC used to
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... ||
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RSVP Control
Messages
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... VCs may not
provide the reliability that RSVP needs. However the best effort
path is expected to satisfy RSVP reliability ...
... reliability that RSVP needs. However the best effort
path is expected to satisfy RSVP reliability requirements in most
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... requirements in most
networks. Especially since RSVP allows for a certain amount of packet
loss without any loss of state synchronization.
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...
As discussed in [6], data associated with multiple RSVP sessions can
be sent using the same shared VCs ...
... VCs. Implementation of such
"aggregation" models is still a matter for research. Therefore, RSVP
over ATM implementations SHOULD use independent VCs ...
... been defined in [7] and [1]. The ability for short-cuts and RSVP to
interoperate has been raised as a general question. The area of
concern is the ability to handle asymmetric short-cuts. Specifically
...
... interoperate has been raised as a general question. The area of
concern is the ability to handle asymmetric short-cuts. Specifically
how RSVP can handle the case where a downstream short-cut may not
have a matching upstream ...
... Path
Figure 2: Asymmetric RSVP Message Forwarding With ATM Short-Cuts
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...
Examination of RSVP shows that the protocol already includes
mechanisms that allows support of the asymmetric paths. The
mechanism is the same one used to support RESV messages ...
... the wrong router and the wrong interface. RSVP messages are only
processed when they arrive at the proper interface. When messages
...
... interface. When messages
arrive on the wrong interface, they are forwarded by RSVP. The
proper interface is indicated in the NHOP object of the message. So,
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... proper interface is indicated in the NHOP object of the message. So,
existing RSVP mechanisms will support the asymmetric paths that can
occur when using short-cuts.
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... The short-cut model of VC establishment still poses several issues
when running with RSVP. The major issues are dealing with established
best effort short-cuts, when to establish short-cuts, and QoS only
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... best effort short-cuts, when to establish short-cuts, and QoS only
short-cuts. These issues will need to be addressed by RSVP
implementations.
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The key issue to be addressed by RSVP over ATM implementations is
when to establish a short-cut for a QoS ...
... when to establish a short-cut for a QoS data flow. RSVP over ATM
implementations SHOULD simply follow best effort traffic ...
... PATH messages are
forwarded over the best effort short-cut. Note that in this
approach, when best effort short-cuts are never established, RSVP
triggered QoS short-cuts will also never be established.
...
... Heterogeneous sessions can only occur with multicast RSVP sessions.
The issues relating to data VC ...
... Braden, R., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205prop ...
... Crawley, E., Berger, L., Berson, S., Baker, F., Borden, M., and J. Krawczyk, "A Framework for Integrated Services and RSVP over ATM", RFC 2382, August 1998. ...