is there any config that i need to do. or that would be best practice with regards to prepping a pair of 3542p powerconnect switches for use on a voip network.
We do not assign passwords to the switches. If you do not know the password on the switch then you can try deleting the startup-configuration. If there is an enable mode password preventing you from this then you will need to call into support for assistance with recovering the password. Account verification will be required before assistance with recovering the password can be provided.
I don't have a list of best practices for VOIP setup. If you have specific questions regarding the configuration I will do my best to assist.
Dell EMC, Enterprise Engineer
Get support on Twitter @DellCaresPRO
As far as the password recovery on the PC 3524P you can go into startup menu and the 3rd option is password recovery procedure. Here is some info from the user guide pertaining to password recovery.
Password Recovery - option
If a password is lost, the Password Recovery procedure can be called from the Startup menu.
The procedure enables entry to the device once without password.
To recover a lost password when entering the local terminal only:
1 From the Startup menu, type  and press <Enter>. The password is deleted.
Enter your choice or press ESC to exit
Current password will be ignored!
NOTE: To ensure device security, reconfigure passwords for applicable management methods.
That will allow you to bypass the password one time and you will then want to assign a password that you will remember. You can view this info at the link below on page 62.
Please let me know if you have any other questions.