FDDI FREQUENCY AND CABLE COMPATABILITY FOR
ITEM: RTA000028021
QUESTION:
We are building an FDDI ring in a pilot mode and need to know the
frequency and cable compatability for various IBM products to include
3172, RS/6000, 8240 and 8250. I see on the various product descriptions
that most seem to support 62.5/125 micron multi-mode fiber. Another
item says the RS/6000 FDDI adapter uses a frequency of 780 nanometers.
I understand the primary FDDI standard is 1300 nanometers.
The question is, can I put a 3172, RS/6000s, 8240 and potentially
an 8250 on the same FDDI ring and will they work? Do I use the
62.5/125 micron multi-mode cable. What frequency does each adapter
support? Finally, is all this information available in one document?
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A: Yes, it is possible to install the various equipment on the same
FDDI ring. The physical and logical links are standardized for FDDI.
ANSI and ISO have defined the Physical Layer Medium Dependent
(PMD) Standard for FDDI to specify power levels and characteristics
of the optical transmitter and receiver, the interface optical
signal requirements, the connector receptacle design, and
requirements for FDDI cabling and permissible bit error rate.
The 62.5/125 fiber is recommended for minimal loss, but other
popular fiber sizes are supported by IBM as well.
The adapter you referred to for the RS/6000 with a center wavelength
of 780 nm would have loss disadvantages, but it will work with the
other FDDI hardware. I'm going to transfer this item to the RS/6000
workgroup to address specific concerns regarding this connection,
and for comments about alternative FDDI adapters for the RS/6000.
To our knowledge, all other IBM FDDI interfaces conform to the
primary FDDI standard.
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A: The RISC System/6000 FDDI adapter conforms to the standards. The
following excerpts are from the "POWERstation and POWERserver Hardware
Technical Reference Options and Devices Supplement (April 1992)"
SN32-9026-00.
1. "The standard specifies a fiber size of 62.5 microns ....... The
light source wavelength is specified at the 1300 nanometer wavelength. "
2. "OPTIC Transceiver
The Optical Transceiver (XCVR) converts the ENDEC's pseudo ECL output to
1330 nano-meter light signal and converts the 1330 nano-meter light
signal into a pseudo ECL CR input.
A XCVR is required for both of the SAS and upgrade adapters.
The functions of the Optical Transceiver are as follows:
Transmit Power -15db min
Receiver sensitivity -28db min
Wavelength 1330 nano-meter typical "
I did not find the reference to the 980 nanometer wavelength in searching
the databases, can you give me more specifics so that I can correct a
possible error.
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QUESTION:
In response to your request for the ASKQ reference to 780 (sic)
nanometer frequency for RS/6000. It is in item 7VPBZ with
a title of HOWTO AIX: SERIAL OPTICAL CHANNEL CONVERTER. It is
entirely possible that I misinterpreted the reference.
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A: The item you reference is correct,
The Serial Optical Channel Converter (SOCC) should not be confused with
fiber optic-based technologies for Local area networks (LANS), such as
FDDI. The Serial Optical Channel and the Serial Optical Channel Converter
are IBM designed for the RISC System/6000 family and use a communication
architecture specific to the IBM RISC System/6000. I hope this clarifies
the issue.
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This item was created from library item Q614205 BWXXL
Additional search words:
BWXXL CABLE COMPATABILIT FDDI FREQUENCY HARDWARE IX JAN93 RISCOHW
RISCSYSTEM
WWQA: ITEM: RTA000028021 ITEM: RTA000028021
Dated: 04/1996 Category: RISCOHW
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