The T.38 protocol is designed to compensate for the differences between traditional packet-less communications over analog lines and packet-based transmissions which are the basis for IP communications. The fax machine may be a standard device connected to an analog telephone adapter (ATA), or it may be a software application or dedicated network device operating via an Ethernet interface.[35] Originally, T.38 was designed to use UDP or TCP transmission methods across an IP network. UDP provides near real-time characteristics due to the "no recovery rule" when a UDP packet is lost or an error occurs during transmission.[36]

It's also possible to switch a call from a mobile device to a desktop line or vice versa. Business products generally offer several pricing levels based on the number of lines needed, ranging from approximately $20 per line for large organizations to $35 per line for smaller groups. Even from an administrative perspective, you should be careful, however, when migrating to a new phone system. Whether you're an individual just buying a new land line or a business moving from an old-style PBX system, or even just switching to a different VoIP provider, the process should be approached carefully and only after thorough planning.
That being said, Grasshopper doesn’t offer any conferencing tools. For that, you’ll have to sign up for—Grasshopper’s sister company. This service offers both video and audioconferencing, but it does cost an extra $10–$30 per month. That’s another strike against Grasshopper, since most providers in Grasshopper’s price range include conferencing features.
Yes it is really this simple. Just connect your telephone adapter to your home Internet by connecting a cable between it and your router or modem. Then connect your existing phone to the adapter and you should be good to go. If you decided to use your own adapter, you will likely be required to run a quick configuration script that is supplied by your service provider.