Guardian Telecom Inc.
Installation and Operation
VoIP Telephone Setup & Configuration
9. I see in the electrical connection diagram in the users guide that there is a High PIV Ultra Fast
switching diode. Do I need it and if so do you have a source?
This High PIV Ultra Fast switching diode prevents CEMF kick back from an intermediary relay coil when
power is cut and the coil field collapses. You could use an On-Semi MUR105 diode or an IN4007, which is
readily available.
Specifications Datasheet
10. We have the Cisco 3550 switch and it looks like the unit is not able to negotiate the power with the
switch. It keeps cycling over and over.
This happens because with default settings, the switch port is resetting power too quickly. Therefore, on the
3550 switch, on the switch port that the unit is attached to, please try adding the following CLI command:
power inline delay shutdown 20 initial 300
That should keep power supplied until the unit can boot up all the way.
11. The Guardian device connected to a Dell Powerconnect 3524P or 3548P port did not stay linked up.
The device comes up, and then it goes down, and then it comes up cycling.
If connected to a Linksys SRW208MP switch, the Guardian device stays up.
Pantel, Cisco, or Linksys PoE endpoints all work on the Dell Powerconnect 3524P.
A user tried hard coding the switch speed/duplex and tried four different Dell Powerconnect 3524P switches.
--- Check to make sure the Dell Powerconnect 3524P has flow control enabled on the port for the Guardian
device to power up properly.
According to Dell:
Flow Control Support (IEEE 802.3X)
: Flow control enables lower speed devices to communicate with higher
speed devices by requesting that the higher speed device refrains from sending packets. Transmissions are
temporarily halted to prevent buffer overflows. For information on configuring Flow Control for ports or LAGs,
see "
Defining Port Configuration
" or "
Defining LAG Parameters
" in the
Dell™ PowerConnect™ 35xx
Systems User's Guide
.
12. I am unable to connect with the unit when it is plugged into a Cisco SLM 224P switch.
The cables or switch ports that you are connecting to are set in
switch
or
hub mode
instead of
endpoint
stations
. The
MDIX
setting needs to be changed to
MDI
since Guardian VoIP products are end stations.
From the Cisco SLM 224P User Guide:
Change to MDI:
MDI / MDIX
Displays the Media Dependent Interface (MDI) / Media Dependent Interface with Crossover
(MDIX) status on the port. Hubs and switches are deliberately wired the opposite of the way end stations are
wired, so that when a hub or switch is connected to an end station, a straight through Ethernet cable can be
used, and the pairs are matched up properly. When two hubs or switches are connected to each other, or two
end stations are connected to each other, a crossover cable is used to ensure that the correct pairs are
connected. The possible field values are: -
MDIX
Use for hubs and switches. -
MDI
Use for end stations.
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