Cabletron Systems NBR-420 사용자 설명서

-

Network propagation delay is the amount of time it takes a packet 
to travel from the sending device to the receiving device. Total 
propagation delay for the entire network must not exceed 25.6 

µ

s 

in one direction (51.2 

µ

s round trip). If the total propagation delay 

exceeds 25.6 

µ

s, you must use bridges.

•

Length - If you meet all system budgets, the maximum single mode 
fiber optic cable length can reach 5 km (3.1 miles) with bridges at each 
segment end. However, IEEE 802.3 FOIRL specifications specify a 
maximum of 1 km (1093.6 yards).

When connecting a thin-net (coaxial) segment to an EPIM-C, ensure your 
network meets the following requirements:

•

Cable Type - Use only 50 ohm RG58A/U type coaxial cable for 
thin-net cable segments.

•

Length - The thin-net segment must not exceed 185 meters.

•

Terminators - Terminate each end of a thin-net segment.

•

Connectors - You can use up to 29 tee-connectors throughout the 
length of the cable segment for host connections.

-

If you use an excessive number of barrel connectors within the 
cable segment (e.g., finished wall plates with BNC feed-throughs), 
you may need to reduce the number of host connections. For 
special network design, contact Cabletron Systems Technical 
Support.

-

Grounding - For safety, ground only one end of a thin-net 
segment. Do NOT connect EPIM BNC ports to earth ground.

Connecting a thin-net segment to earth ground at more than 
one point could produce dangerous ground currents.