Metrodata MetroLAN-1000, Подробное краткое руководство по эксплуатации

Страница: 22 / 28

QUICK START CONFIGURATION
18 76-02-059A
4.7.2.7 Max Differential Delay Compensation
In most cases the default setting of 32ms is sufficient, however if a large number of VC-12
tributaries have been allocated and they are routed via very diverse routes this may need to
be increased to the maximum of 48ms. An alarm will be raised to indicate that the differential
delay setting is too low.
4.7.2.8 J1/J2 Strings
Each tributary assigned to a LAN port may have an individual Path Trace Identifier
configured. For VC-3 tributaries it is the J1 string, and for VC-12 it is J2. In both cases a 16
byte string made up of 15 user characters and a single CRC-7 byte are used. The user may
configure the following on a per tributary basis:
J1/J2 Transmit: “String of up to 15 alphanumeric characters"
J1/J2 Receive: "String of up to 15 alphanumeric characters"
If an expected J1/J2 receive value is configured, the MetroLAN will declare a TIM alarm
when there is a mismatch between the configured expected and actual receive J1/J2
identifiers. Since there may be many tributaries assigned to a single LAN port, there is the
option of including the tributary number automatically such that the first four characters
become
klm, leaving 11 characters for the user string. Similarly once the label has been
defined it may be copied to all tributary group members.