We recently switched over to LTE broadband at home. Our previous provider (British Telecom) struggled to offer anything faster than ~35Mbps download & ~4Mbps upload, perhaps owing to the particularly long run of wet string copper cable between our property and our VDSL DSLAM.
Considering LTE
A few speed tests with SIMs from different providers showed that Vodafone were able to offer at least ~80Mbps download and 30Mbps upload most of the time, which suited us fine. If you are considering LTE broadband, I’d strongly suggest buying a cheap data card & USB adapter and a variety of Pay As You Go SIM cards from different providers to experiment with. Try different locations around your property – particularly upstairs windows to see which provider and installation location provides the best performance.
LTE (4G) broadband has a few downsides to consider too. Principally – latency (the time taken for a packet to complete a round-trip from one host to another) & jitter (the variation in latency over a period of time). Due to the modulation techniques and media-sharing inherent in their design, wireless links are nowhere near as performant or as stable in the latency department as typical wired connections. This can have an impact on jitter-sensitive applications such as video calling and VoIP, so if this is the sort of application you’ll be primarily using, LTE broadband might not be the best choice.
There is another thorny issue with LTE broadband that presented a much greater challenge…
CGNAT
CGNAT stands for Carrier-Grade NAT. It is a type of large-scale NAT (Network Address Translation) used by carriers to deliver Internet service to large numbers of users. One of the primary uses of CGNAT is to limit the number of public IPv4 addresses that are issued to subscribers. This has become a more pressing issue in recent years owing to the emergent IPv4 address exhaustion issue.
Most LTE broadband providers use CGNAT. The IP address subscribers receive is a “private” IP address (typically within 100.64.0.0/10, which is specifically designated by IANA for this purpose, however the 172.16.0.0/12 block is also sometimes used owing to it being uncommon in consumer private networks).