IP-NET, LLC
VQE1 User Manual V1.3
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Correct timing mode setting is important for smooth operations. In most cases,
setting both units to adaptive timing mode is sufficient. But sometimes, setting one unit
to loop timing mode may work better. For example, setting the VQE1 unit connected with
the clock master (such as local exchange) to loop back mode, and the other unit
connected with the clock slave (such as PBX or remote module) to adaptive mode, is
probably better than setting both to adaptive modes.
One typical error in telecom applications is to connect two communication devices
that are both clock slaves. Neither VQE1 will support such operation no mater how the
timing modes are set.
Note: that the E1channel emulation takes several minutes to stabilize.
During that period, clock drift may exceed the limit, errors and slips may occur.
Various timing schemes are enlisted in Table 1.4-1, for applications depicted in
Fig.1.4-2.
Fig.1.4-2 Timing mode scheme reference diagram
Table 1.4-1 Timing mode schemes
Equipment
A clock
mode
Equipment
B clock
mode
A side
EthMux V4
Timing
mode
B side
EthMux V4
Timing
mode
Note
loop back
loop back
master master
adaptive adaptive
Equipment A & B
clocks synchronous
master master adaptive
adaptive
Equipment A & B
clocks
plesiochronous
loop back
adaptive
master slave
adaptive adaptive
adaptive loop
back
slave master
adaptive adaptive
slave slave
Not
allowed
Note that setting both units to adaptive timing mode works well for all the conditions,
although the other option may work better.
Equipment
A
DOCSIS
or Packet
Network
A side
VQE1
B side
VQE1
Equipment
B
RF or
10/100 Base T
RF or
10/100 Base T
