NetXpress LX & CM-30R Installation & Operation Manual
2
–
Functional Design
Version 1.1
2-18
GatesAir, Inc.
Intraplex Products
FEC HIGH (used in more serious packet loss conditions)
Triple error correction is engaged. This scheme introduces a 100% overhead (increased bandwidth
required) and can correct one, two, or three consecutive packet losses. In this scheme, the packet
sequence sent is critical if it is to protect against consecutive packet losses.
Table 2-3 shows the NetXpress LX performance data, with an overall loss rate and a percentage of
high versus low FEC loss.
Table 2-3. NetXpress LX FEC Performance Data
Network
Loss
Rate
(%)
High
FEC
Loss
(%)
Low
FEC
Loss
(%)
1
0.0017
0.027
2
0.0023
0.085
3
4
5
0.0168
0.507
6
7
8
9
10
0.14
2.1
11
12
13
14
15
0.597
4.87
% High FEC Loss ((Lost packets / Rx packets) x 2) x 100
% Low FEC Loss ((Lost packets / Rx packets) x 1.5) x 100
2.9 Power
The system runs on either AC or DC power supplies. The NetXpress LX-100 multiplexer supports 30 W
AC powered. The NetXpress LX-300 multiplexer supports 60 W and 95 W AC powered or 50 W DC
powered supplies.
The NetXpress LX-300 system also supports redundant power supplies. You can install a main power
supply and a redundant supply in case the main supply fails. Section 3.2.4
–
Power Supply Installation
gives more information on NetXpress LX power supplies.
2.10 Voice Signaling
Voice signaling communicates voice channel call progress information over a data link. The
information, known as ABCD bits (or E & M) includes busy, idle, or other ringing state indications to
alert the caller that a call is taking place. Two types of voice signaling are robbed-bit signaling (RBS)
and channel associated signaling (CAS).
