Hi Vijay,
When attempting to access the IVR, the system usually takes longer if a DHCP server is not available.
Also, don't expect to hear a dial tone, just lift the handset and press asterisk four times **** and you should hear the IVR menu. Try this at least 5 times, about 30-seconds to a minute after providing the device with power...
If you still cannot get to the IVR, you can attempt to recover the device, but the devices usually only need recovery if they failed during an upgrade if power was removed or the network failed, so I doubt that yours needs recovery.
The recovery tool is available here: https://www.myciscocommunity.com/message/8738#8738
You cannot factory reset or upgrade the device without access to the IVR or the web-ui...
Regards,
Patrick
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