IP-NET, LLC
VQE1 User Manual V1.3
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2.
System architecture
2.1
Block diagram
The internal functional structure of VQE1 is depicted below:
Fig. 2.1-1 Functional diagram
2.2
Description
The heart of VQE1 is the TDM/Packet processing unit. It truncates E1 data stream,
putting the data into Ethernet packet with or without IP headers. The packets are
passed to the Ethernet switch unit via MII interface, and are sent out adaptive through
the uplink port to the WAN port of the RF MODEM module for transmission via a DOCSIS
network, or through a Daisy-Chain up to another VQE1. Ethernet data from two local
data port are also sent out through the uplink ports, but with lower priority than those
packets containing E1 data.
In the reverse direction, packets from the RF MODEM or the uplink ports are sorted
at the switch unit. All but E1 packets are passed to the local data ports. The packets
containing E1 data are sent to the TDM/Packet processing unit for reassembly of the
original data stream, and recovery of the E1 clock which is the key element of the
device. A very sophisticated algorithm is used to ensure that the reconstructed clock will
meet the stringent requirement of TDM applications. The most important parameters
are jitter, wander, and signal delay.
The control unit interfaces with the user through a console port so that various
operational parameters can be modified.
2.3
Front panel
2.3.1
Diagram
VQE1 is shown in Fig. 2.3.1-1.
Fig. 2.3.1-1 Front panel of VQE1
DIP Switch
E1 Alarm Status
Ethernet Status
Cable Modem Status
RF
Modem
Main Status
Far-End Status
