I have a problem regarding my Polycom Soundpoint IP331. It doesn't boot anymore. It shows only an error which is error.cfg.

yes, yes it is.... what a pile of crahp

Makes sure your Firmware is all upto date. Had the same issue with the soundpoint ip 501.

Try this password 9418941962

1st. Get the IP address of the phone. and type that into browser.
*- default user: Polycom / password: 456

*- Under menu SIP, type in your voip provider
*-Under menu LINES type in user info and "secret" should be your password.

Make sure your ports are open (SIP is usually 5060) you can change it in that same config screen.

This occurs when the phone is set up to load it's configuration file from a ftp or tftp server and it cannot find the file or server location. If the phone is supposed to do this, please check that the ftp or tftp service is running on the specified server. The server name or ip is specified in the setup of the phone, available when the phone is first booting up. The default username is 'Polycom' and password is '456'. If you DO NOT want your phone to get it's configuration from a network server, enter the setup area and remove the server name or IP address from the appropriate section.

Can you pls check the configuration file on the tftp server
some wrong information is there
pls compare with any other ip phone

This means the phone cannot find its <mac>.cfg file on the boot server, and does not have one loaded in its own flash memory.
You will need to configure a boot server to host the SIP software, BootROM, and all the config files (these are included in with the SIP software).
You can download these from Polycom's product support page:
http://www.polycom.com/support/voice/soundpoint_ip/soundpoint_ip330_320.html

This means the phone's SIP application has been erased. You will need to download the SIP app and BootROM from the Polycom support page, host the files on a boot server, and then point the phone to this server from the server menu so the phone will reboot and download the files.

http://www.polycom.com/support/voice/soundpoint_ip/soundpoint_ip330_320.html

Make sure you have the latest BootROM and SIP config files for this polycom(sip.ld, sip.cfg, etc...) on your TFTP server. If you do not have this - download from here - http://www.polycom.com/support/voice/soundpoint_ip/soundpoint_ip501.html

If you do not have a TFTP server, you can download one for free.

This means the phone's SIP application has been erased. You will need to download the SIP app and BootROM from the Polycom support page, host the files on a boot server, and then point the phone to this server from the server menu so the phone will reboot and download the files.

http://www.polycom.com/support/voice/soundpoint_ip/soundpoint_ip330_320.html