Transcript
ETHERNET
Half/Full Duplex Converter NH 201A
Overview
Description
The NBase NH 201A is a compact, two port converter operating in the Ethernet environment. The unit converts a half duplex connection into a full duplex one with no distance restrictions.
The NH 201A is an IEEE 802.3 Standard converter. The unit incorporates buffered/on-the-fly forwarding, resulting in runt filtering, yet providing near zero port-to-port forwarding latencies.
the transceiver and cable used. The media propagation time is NOT a factor in full duplex communication, since full duplex eliminates the need for collision detection.
The NH 201A also splits a network’s collision domain, reducing contention and eliminating fragments created by the collision process on the half duplex segment.
Under the same conditions, a point-topoint, full duplex Ethernet segment could be 50km or 100km in length, using singlemode fiber and the NX 300FO/SX AUI FOT from NBase.
The NH 201A is a protocol transparent device that can extend the range of an Ethernet network far beyond the conventional CSMA/CD-imposed limits.
Features s
No fragmented packets or runts
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Plug ‘n work
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Near zero port-to-port switching delays
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Complies with IEEE 802.3 Ethernet Standard
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AUI connectors
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Extends the range of Ethernet networks
Theory of Operation The maximum length of a standard Ethernet segment is determined by the round trip media propagation time, the maximum data rate and the smallest valid frame length. For example, at a maximum data rate of 10Mbps and a minimum frame size of 512 bits, the minimum slot time is approximately 50µ. The slot time is the period of time that a standard half duplex Ethernet transmission is monitored for a data collision. Light travels about 10km over fiber during a 50µ interval, making the cable for a 50µ round trip time of approximately 5km in length. Therefore, the maximum length for a standard Ethernet segment over fiber is 5km. The maximum length of a full duplex Ethernet segment, however, is limited only by the specified capability of
Figure 1: Long Distance PPP Ethernet Link
Half/Full Duplex Converter -- NH 201A
Figure 2: Full Duplex Switched Ethernet in a Campus or Metropolitan Environment
Technical Specifications Compatibility
IEEE 802.3
Buffers
Up to 192 packets
Forward Rate
In both directions
Switching Delay
Measured from first input bit to first output bit
60µs
Diagnostic Leds
Power Activity
1 x Green 2 x Green
Connectors
AUI
Electrical
Line Voltage
Physical
Size H x W x L 1.8” x 7.8” x 8.5” 4.57 x 19.81 x 21.59cm
Environment Standards Compliance
10Base-5 FDSE (Full Duplex)
14,880 pps / 14,880 pps
Unit is powered Indicates Ethernet traffic 10Base-5 90 VAC to 260 VAC 47-63 Hz 20W Weight 2.0 lb max. 906 gr
Operating Temperature
Storage Temperature
Humidity
100 C to 500 C
-400 C to 700 C
10% - 90% non-condensing
500 F to 1220 F
400 F to 2480 F
UL-1950, TUV, FCC Part 15, Class A, CE
Ordering Information
NBase Communications Representative
NH 201A ................................................................................Half Duplex to Full Duplex Converter NX 300FO/M ............................................................AUI to 10Base-FL Multimode (850nm, 0-2km) NX 300FO/MX ..............................................................AUI to Fiber Multimode (1300mm, 0-5km) NX 300FO/S ................................................................AUI to Fiber Singlemode (1300mm, 0-18km) NX 300FO/SX............................................................AUI to Fiber Singlemode (1300mm, 15-35km) NX 300FO/SY............................................................AUI to Fiber Singlemode (1300mm, 30-60km) NX 300FO/SZ ..........................................................AUI to Fiber Singlemode (1550mm, 40-110km)
© 1996 NBase Communications. All rights reserved. NBase Communications and MegaVision are trademarks of NBase Communications. All other trademarks and trade names are the property of their respective owners. NBase Communications assumes no responsibility for any errors or omissions. All specifications are subject to change without notice. ML41163 Rev. 1.00 - 04.96
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