AES-GCM -- what is ICV and what happens if I don't use it I am interested in using AES-GCM and after hours of reading on Internet I still have a few questions:

What will ensure the ICV, is it only Integrity ? If I don't need it on my purpose, can I spare it and still have secure encrypted data on my channel ? (If integrity is not verified, my packet will be dropped anyway)

our aim is just to encrypt data so that no one can get the information. 

Thanks
ICV is the integrity check value (beware that it may also mean Initial Chaining Value). You cannot do without for GCM mode.

I'm not sure what you mean with: "If integrity is not verified, my packet will be dropped anyway". GCM uses an authentication tag which provides cryptographic integrity. Unless you have another way of adding cryptographic integrity then you cannot just skip verifying the tag.

If you do have another authentication tag, say HMAC over the ciphertext, then you don't need GCM. You could use AES-CTR mode instead. Except for some changes during initialization AES-CTR mode is used within GCM to provide confidentiality.

Beware that GCM and CTR modes do directly leak the plaintext size and possiblty timing information. That's something to solve - or not - at protocol level.