- ...
etc.)1.1
-
the IEC 958 standard specifies the digital interface as carrying up to
20 bits per channel, at 32KHz, 44.1KHz or 48KHz
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- ... allocations.3.1
- In the next version of IP, IP version 6, the address space is 16 bytes
(or octets) in size, and the address space for multicast has been
allocated as starting with 8 ``1'' bits. Interworking between IPv4 and
IPv6 multicast address sessions is relatively straightforward
compared with unicast addresses, since they are already dynamic
entities, so that there are already ways for hosts and routers to
interact to establish receiver membership locations.
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- ... interface3.2
- there
may be some interaction with firewalls here, and this is discussed in
chapter 10
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- ... network3.3
- even when this is
not really the case, such as with a hub-switched ethernet, it maintains the
illusion of such
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- ... 33.4
- currently being discussed, but not yet implemented in late 1997.
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- ... tree3.5
- strictly speaking it's a reverse
shortest path tree - typically the routers don't have enough
information to build a true forward shortest path tree
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- ...
based.3.6
- Yes, we know telemetry could be real timeish....but we
are trying to illustrate major differences clearly for now.
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- ... reflector)3.7
- CU-SeeMe is a popular MAC and PC based
Internet video conferencing package that currently does not directly
use IP multicast.
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- ... 3.6Khz).4.1
- This also has the effect of eliminating
aliases, which are harmonic, or higher frequencies which appear
at the same inter vales as the actual frequencies that we want to have
in our digital signal, but more frequently.
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- ... 140Mbps.4.2
- To
be more precise, the CCIR 601 standard defines a raw 4:3 rate of the
full digitized TV signal as 270Mbps, including the non-visible lines,
the time for interframe synch and so on. Without all this redundant
information, the pure PAL and NTSC visible components can be coded
uncompressed at 143 and 177 Mbps respectively.
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- ... MIPs4.3
- MIPs:
million instructions per second - a common measure of CPU performance - too
simple for subtle work, but good enough for back of the envelope
estimates.
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- ... recovery.5.1
- There are exceptional circumstances
where automatic repeat request protocols may be useful for multimedia,
for instance on local area networks where the delay incurred may be
tolerable. However, these are usually networks that have relatively
low error rates, and FEC ma be more acceptable here too. The main
specialist area where ARQ might really be needed might just be
wireless LANs.
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- ...
based.5.2
- Yes i know telemetry could be real timeish....but we
are just trying to illustrate major differences clearly for now.
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- ...
coupled7.1
- We define a tightly coupled system as one which attempts to
ensure consistency at all sites. By contrast a more loosely coupled system
tolerates inconsistencies, though it should attempt to resolve them in
time. A very loosely coupled system will not even know the full list of
conference members.
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- ... applications7.2
- Actually IVS does support audio, but has also been widely used as
a pure video codec with vat as the audio tool.
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- ... multicast7.3
- or broadcast, but that is outside
the scope of this document, as it does not usually provide a reverse path
from receiver to sender
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- ... applications7.4
- actually many shared
workspace tools will not scale anyway, but we shall concern ourselves here with
those that will
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- ... shift7.5
- For once, we believe the use of the word
paradigm is justified here, in its normal sense of ``pattern''.
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- ...
load8.1
- load, in terms of messages on any particular link, state
or processing power
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- ...
scale8.2
- we would like components to scale O(1). At the
very worst, no component should scale worse than O(n), and even O(n) is not acceptable in some circumstances.
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- ... available.8.3
- This may in fact be a feature of the way
that the application is structured in any case. For example, if the
application state is the same as the effect of the
sequence of messages (as is the case with a whiteboard), then it may
be possible to cast a repair in terms of application state - i.e. to
reconstruct a message that has the same effect as the missing one.
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- ... networks8.4
- and is it really worth
video conferencing with your next door neighbour?
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- ... will8.5
- this
limits the amount of storage necessary for receivers participating in a
possible repair. It is derived from the fact that there are many kinds
of ways to send descriptions of object locations, velocity, trajectory.
Some are coded so that loss of a single message makes it hard to
recover, whilst others are largely simply lists of deltas, and
recovery may be reasonably easy, whilst others are explicit
coordinates, and only the latest message is relevant.
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- ... fields9.1
- The use of text based
protocols is still controversial. The proponents claim it provides
easier design, the assumption of Least Common Denominator, the
ability to use powerful tokenising tools, debugging capabilities and
to easily extend via self describing fields, against slightly more
complex specifications and a less efficient protocol
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- ... servers9.2
- One of the key designers
also works at Netscape...
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- ... participant10.1
- Since the voice
characteristics which make voices unique are removed in compressing
speech, it becomes easier to produce good copies of someone else's
speech - how many times have you been mistaken for someone else on
the 3 KHz telephone?
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- ...
networks10.2
- Ponder the irony that the US DoD funded the design
of the very open Internet...
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- ... requests.10.3
- Of course, it is a lot easier to
design a scalable key distribution protocol in a symmetric capacity
network such as the current day Internet, than in an asymmetric system
such as the current day cable TV net, or proposed IP on ADSL and Cable
Modem networks!
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- ... Fields.10.4
- knowing
what a Galois Field represents another convenient barrier to breaking
such systems:-)
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- ... tunnels.10.5
- recent work is addressing this problem.
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