I have done reviews on Amazon.com, in particular on the old Ericsson / Net America L21 4G LTE router. By doing reviews you often get asked questions from viewers on there … even if you aren’t the person selling the product.
Well I bought one relatively cheap, so I will have to look into a cheap sip service. I wanted this to provide data service and a conventional landline (for an alarm dialer and remote control equip I already own) from a SIM card for a remote property I own. I have Att service and their 2g gsm service (current alarm system) is going away this year, and figured this would suffice. Like the idea of wifi, Ethernet (for ip camera/video doorbell) and a pots line in one device that would work after the gsm service goes away. Not sure if this will do this the way I am thinking. Question, the w35 has a rj-11 that can give me a dial tone using the old circuit switched service for voice you speak of, and will that service be going away when 2g gets turned off. Suggestions? Advice? And thank you for your advice so far.
MY ANSWER:Alan Spicer says:
I used Voip.ms for several customers on boats with the L21. I believe I had to use INBAND signaling (DTMF aka Touch Tones) for inbound control touch tones. I switched from another one for exactly that reason.
I believe CS was carried over to 3G as well as it was still used for voice calls and has been to date for most carriers. It MIGHT not go away when 2G is sunset (turned off.) But I would check with the carrier to be sure. Good luck in finding someone that can understand and answer such questions. The dial tone, by the way, is coming from the W35 itself … not the cell carrier. Cell carriers don’t send a dial tone. That’s just the W35 giving you comfort and telling you it does have voice telephone dialing capability up and running and can make your cellular phone call.
VoLTE is … is going to be … the voice (and more) calling protocol in 4G LTE. The latest mobile phones already have it built-in. The problem is finding a router device like W35 that has VoLTE. Most of the US manufacturers don’t seem to care about voice. It used to be a big thing for Landline Replacement in the earlier days with Ericsson and Telular having RJ-11 jacks. I guess so many people got smart phones that not many want to replace wired telephone any more. They just want data for business primary or backup service, for example, for small sites in retail. The W25 and W35 really were magic bullets for quite a number of years. But like the song Video killed the Radio Star, 4G wants to kill the CS voice star. Since it’s all data network now … either VoLTE for voice or anything else like SIP/Voip that you can bolt on to a router seems to be it. It was cool that the L21 had the Voip and even a Mini-PBX built-in. It was frustrating and fun making them do the things that you are talking about.
2G networks are inherently circuit switched networks. 2G networks were initially developed to be voice-only and were thus circuit switched. Packet switched extensions to 2G networks came in the form of GPRS(General Packet Radio Service) which was used to provide internet services on GSM handsets, and later on EDGE (Enhanced data rates for GSM Evolution). GPRS is often termed 2.5G and EDGE 2.75G.
3G networks, are hybrids of circuit switched and packet switched networks. Packet switching is used for providing internet services and circuit switching is used for voice calls.
4G networks are fully packet switched networks. 4G networks use packet switching for voice calls as well as data, thus offering speeds much higher than 3G.
3G, to be complete, was all about faster data bringing in HSDPA – High Speed Downlink Packet Access, and later also HSUPA – High Speed Uplink Packet Access … which wrapped up together just became HSPA – High Speed Packet Access.
GSM – was great for a long time … because it was a worldwide thing … and computer circuit boards – aka – cellular cards and phones could be used worldwide. The cards had all of the frequencies to work anywhere around the world. It was just a matter of changing SIM CARDS to travel worldwide.
4G LTE means to do away with GSM. 4G LTE because of the frequency wars (digital TV transition) the FCC auctions and equivalents worldwide … turned out many different frequency bands not only in the U.S. but Worldwide. 4G LTE didn’t have Voice – up until recently voice has still been 2G – 3G CS voice. Newer devices now have VoLTE and the carriers are rolling this out in their networks.
Router manufacturers are pretty much stuck with what the Cellular Card manufacturers provide. And it takes a long time to implement a new card in a router. Newer cards can now take modem firmware changes and actually change cell carriers in the U.S. It still takes 2 modems (or routers) to make a Worldwide Capable 4G LTE System. The next newer card will take some of this pain away and have the modem firmware’s onboard on it … and may even take us on the way back towards Worldwide Capability – if and when the router manufacturers implement it. Now trying to get the router manufacturers to also include voice? That is an interesting one … the problem is … Is it Interesting for Them?