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New Member

VG224 Line voltage

The line voltage for all VG224 ports is low (10-11V).

I have change the idle-voltage to high and the impedance to 600r, and it still didn't do any change.

Does anybody know how to solve this problem? i need at least 24 volts to operate my analog phones

  • IP Telephony
Cisco Employee

Re: VG224 Line voltage


The VG224 Line voltages are documented at:

The idle-voltage low setting designates -24 V and the idle-voltage high setting designates -48 V.

There's a bug: CSCsc74959 that explains why you can get 37V instead of 48V, but apparently you are still getting a low voltage even though you

set it to high, correct?

Make sure you configured the idle-voltage high under each voice port and try doing a shut/no shut to the port too.

If you measure the voltage how much do you get? and what IOS version are you using?

Hope this helps! If it does, please rate :)



Regards, Tere. If you find this post helpful, please rate! :)
New Member

Re: VG224 Line voltage

i made sure all the ports are configured with idle-voltage high. I also didd shut/no shut on every ports. Still getting a measured voltage of 10V to 11V.

The version is 12.4(6)XE1. The other thing is that i have 2 other units (VG224) configured exactly the same with the same version number and they work fine. Also as i remember this gateway was working fine before

Cisco Employee

Re: VG224 Line voltage

Can you try using the "no battery-reversal" on the voice-port? And see if this helps?

Regards, Tere. If you find this post helpful, please rate! :)
New Member

VG224 Line voltage

We are facing the same issue, when you set idle-voltage high, it is not showing when you check the running config or do a show voice port..

Any ideas?

We are running an MGCP VG224 Version 12.4(22)T5

Anyone able to fix this? Is it a bug?

VG224 Line voltage

Try this command

vg(config-voiceport)#alt-battery-feed feed2



New Member

We run multiple vg224 and the

We run multiple vg224 and the maximum we can get is 39v on idle-voltage high. As we know vg224 can only go 43v and in order to get that i used alt-battery-feed feed2.


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