Enterasys mrxi-22 User Guide
INSTALLATION REQUIREMENTS/SPECIFICATIONS
2-2
2.3
NETWORK GUIDELINES
Take care in planning and preparing the connections and the cables for
your network. The quality of the connections, the length of the cables, and
the location of the MRXI are critical factors in determining the reliability
of your network. The following sections describe the network guidelines
to operate this equipment.
your network. The quality of the connections, the length of the cables, and
the location of the MRXI are critical factors in determining the reliability
of your network. The following sections describe the network guidelines
to operate this equipment.
2.3.1
10BASE-T Twisted Pair Network Requirements
The device at the other end of the twisted pair segment must meet IEEE
802.3 10BASE-T specifications. When you connect a 10BASE-T Twisted
Pair Segment to the MRXI’s 10BASE-T Twisted Pair Ports, the following
network requirements must be met:
802.3 10BASE-T specifications. When you connect a 10BASE-T Twisted
Pair Segment to the MRXI’s 10BASE-T Twisted Pair Ports, the following
network requirements must be met:
•
Length
- The IEEE 802.3 10BASE-T standard requires that
10BASE-T devices transmit over a
100 meter
(328 foot) link using
22-24 AWG unshielded twisted pair wire. As a general rule, links up
to 130 meters in length for unshielded twisted pair and 200 meters in
length for shielded twisted pair are achievable. For each connector or
patch panel in the link, subtract 12 meters from the 150 meter limit.
This allows for links of up to 126 meters using standard 24 AWG UTP
wire and two patch panels within the link. Higher quality low
attenuation cables may be required when using links of greater than
126 meters. Due to cable delay, the maximum link length is always
limited to 200 meters, regardless of the cable type.
to 130 meters in length for unshielded twisted pair and 200 meters in
length for shielded twisted pair are achievable. For each connector or
patch panel in the link, subtract 12 meters from the 150 meter limit.
This allows for links of up to 126 meters using standard 24 AWG UTP
wire and two patch panels within the link. Higher quality low
attenuation cables may be required when using links of greater than
126 meters. Due to cable delay, the maximum link length is always
limited to 200 meters, regardless of the cable type.
•
Insertion Loss
- The maximum insertion loss allowed for a
10BASE-T link is 11.5 dB at all frequencies between 5.0 and 10 MHz.
This includes the attenuation of the cables, connectors, patch panels,
and reflection losses due to impedance mismatches in the link
segment.
This includes the attenuation of the cables, connectors, patch panels,
and reflection losses due to impedance mismatches in the link
segment.
•
Impedance
- Unshielded twisted pair cables typically have an
impedance of between 85 to 110 ohms. Shielded twisted pair cables,
such as IBM Type 1 cable, can also be used. You should remember that
the impedance of IBM Type 1 cable is typically 150 ohms. This
increases the signal reflection caused by the cable, but since the cable
is shielded, this signal reflection has little effect on the received
signal’s quality due to the lack of crosstalk between the shielded cable
pairs. Cabletron Systems 10BASE-T Twisted Pair products will work
on twisted pair cable with 75 to 165 ohms impedance.
such as IBM Type 1 cable, can also be used. You should remember that
the impedance of IBM Type 1 cable is typically 150 ohms. This
increases the signal reflection caused by the cable, but since the cable
is shielded, this signal reflection has little effect on the received
signal’s quality due to the lack of crosstalk between the shielded cable
pairs. Cabletron Systems 10BASE-T Twisted Pair products will work
on twisted pair cable with 75 to 165 ohms impedance.