voip phones wont work on xb8 cable modem

I'm a VOIP engineer at a large organization.  Multiple people use Xfinity to work at home with a VOIP phone.

Its common knowledge in the IT world for any VOIP technician to know that SIP ALG causes mutliple problems with VOIP phones losing registration or not registering at all.

Xfinity is now handing out the new XB8 cable modem.  This modem does NOT have an option to disable SIP ALG which is leading to a large number of users not being able to work at home.

To compound the problem, xfinity support doesnt even know what SIP ALG is, so trying to get support is beyond frustrating.  Thankfully, i'm an advanced user and know to just go buy my own modem and disable that feature.  

If you run into this issue, you will need your own modem.  Most common models let you disable this feature.

It may even be an option on the xb8, but Xfinity Support has no idea how to do advanced administration on this device.