@make[report]
@majorheading[Camtec]
@section[General]
In view of the position of CAMTEC as suppliers in the Academic Community
this report is in the form of an update only.
@section[Hardware Description]
The CAMTEC switch PAD contains a new board consisting of a M68000 processor,
1/4 megabyte store, 4 synchronous line interfaces and a Ring interface.
Either one or two of these boards can be combined with the Z80 processor
board and 128Kbytes of store found in a standard PAD.  It is expected that
eventually 4 M68000 boards could be used.

A CAMTEC Ring Switch consists of up to 6 Ring Gateways interconnected by a
dual Cambridge Ring.  In this configuration the line speed is constrained
to the 19.2Kb/s of the Ring Gateway.  The code in the Ring Gateway has
been modified so that X.25 packets can be carried across the Ring in a non
Ring-standard fashion.

There will be a further development that uses switch PADs interconnected by
Cambridge Ring but this will not be available before the summer of 1986.
@section[Software Description]
The Z80 is being used to move packets between the M68000 boards.  Only
packets that need to be switched to another M68000 board are handled by 
the X80.  On the current releases of software the X80 handles all call
setups and clear downs although this should change in the longer term.
@section[Configuration Options]
On a single M68000 card, 2 of the lines can run at 64Kb/s, the other two
can be currently run at speeds up to 19.2Kb/s and it is hoped that they 
will run at up to 38.4Kb/s in the first quarter of 1986.
@section[Line Speeds/Interface Options]
V24 is used for speeds up to 19.2Kb/s, X.21 is used for higher speeds.
V35 is not supported although a converter between X.21 and V35 is available 
(not from CAMTEC).  Internal speeds of 2.4, 4.8, 9.6, 19.2, 38.4, 48 and 61K
are supported.
@section[Throughput]
A throughput of 100 data packets/sec is claimed for a M68000 board.  The
X280 will be a limitation on the throughput of an entire switch, although
a maximum 50,000 bytes/sec is claimed once the X80 is relieved of other
duties.
@section[Costs]
The following costs are given in two parts, first the cheapest way
to put the unit together, ie. using existing PAD channel boards to provide
the 9.6kb/s lines and the second using all 68000 cards with a minimum
line speed of 19.2kb/s.  The costs are 'Academic Community' prices.
@begin[verbatim]
     10 Lines  JNT PAD with single upgrade           @T{#}4,500
               Full switch box, ie. 3 x 68000 cards  @T{#}8,240

     18 Lines  Single Switch PAD with 10 Z80 lines,
               8  68,000 lines                       @T{#}7,500
               Switch 16 + 4 ports Minipad
               (budgetary price)                    @T{#}11,9000

@end[verbatim]
@I{N.B.  Both these options require a Switch PAD with 4 line cards in it
rather than the current 2.}

There are plans to create switches to meet the 48 line or 100 line switches
but as there is no possibility of them before late 1986 the costs have been
put in an annex to the report.
@section[X.25 Facilities]
Fast Select, Packet & Window negotiations, Call Redirection and Reverse
Charging are supported.  Call Statistics are not supported although CAMTEC
are 'now aware of the progblem'.  CAMTEC are now committed in a contract to
implement PVCs.  The current maximum window size is 256 bytes, it is hoped
to increase this to 512 bytes by the third quarter of 1986.

CAMTEC use 'simple' X.25 between network nodes.  Ther is uncertainty as to
whether Network Clearing Codes can be passed.  No special action is taken to
retain calls if a transit node, or its links, break.
@section[Addressing]
CAMTEC use an address match scheme to construct address tables.  There can
be single, 'ranges' or mixtures of both types.  The 'ranges' mechanism is
restricted to match on the first 'n' digits and the common failing of this
scheme, ie. address 1234 is not the same as 000000001234 applies.

No proper load sharing.
@section[Network Management]
The current network management in the switch PAD is extremely limited.
There is no data collected for each call, there is a very limited performance
measurement and there is no warning of fault conditions.  There are plans to
provide such information but it is in Release 4 of the software, not expected
before mid 1986 at the earliest.  When it is released it will use DEC Micro
VAX II.  There are plans to use an IBM PC but that will be even later.  A
special 'block' protocol will be used and CAMTEC are prepared to put this
protocol in the public domain but not before the end of 1986.
@section[Statistics]
Only counts of data packets are provided.  Any more facilities will await
Release 4, ie. not before mid 1986.  The current pland are not to use local
console at all so all collection will be have to be performed remotely.
@section[Operator Control]
It is not possible to enable or disable a link or clear a call to a selected
DTE address.  It is not possible to change line speeds, LCNs or the DCE/DTE
sense on a running system.  These features are atgain promised in Release 4
or even the second version of Release 4.
@section[Date-Time Stamp]
Not before Release 4.  The NMS will then hold the time and correct the time
in PADs and switches.
@section[PSS Compatibility]
Compatibility is committed.
@section[Performance - Packet Transmission]
The following times were measured on a 6mhz PAD.
@begin[verbatim]
               Call request     61.6ms
               Data Packet       5.2ms
               Clear Request     5.2ms
@end[verbatim]
It seems unlikely that a switch PAD will do better on Call Requests as it
will still use the 6Mhz PAD.
@section[Availability and Reliability]
The hardware is claimed to have an MTBF of more than 2000 hours, no promises
were made for single units on the software MTBF.
@section[Operation]
Complies, apart from the ability to dump.
@section[Reconfiguration]
Complies.
@section[Known Problems]
The switch PAD, even in its first full release scheduled for January 1986
does not meet the spec in a whole number of points.  It remains to be seen
to what extend the Release 4 software will, and what the timescale for its
release will be.
@section[X.25 (1984)]
Implementation of the ISO Network Service has been committed for the MSC
network by the end of 1986.  There is a realisation that options will be
required for the various versions.
@section[Academic Community Special Requirements]
? ask
@section[Product History]
Known.
@section[Company Information]
Known.
@section[Contact Name]
Known.
@section[Confidentiality]
CAMTEC is sensitive about the details of the backplane, for example the
constraints caused by using the Z80 processor.
@section[Summary]