On 07/29/2018 12:14 PM, Andrei Borzenkov wrote:
Отправлено с iPhone
29 июля 2018 г., в 17:34, James Knott
написал(а): WiFi is available on many phones here. It uses the same protocol as VoLTE (Voice over LTE), but connects via WiFi. If the phone also has VoLTE enabled, it can transition seamlessly between WiFi and the cell network. WiFi calling has absolutely nothing to do with VoLTE. The whole point of WiFi calling is to allow connection to *any phone* without any need to have data services on other end. It connects to your mobile operator over internet which then forwards call over voice network. Actually WiFi calling is the most interesting exactly when you want to reach someone on normal (e.g. PSTN) phone, as otherwise there are enough applications you can use to communicate over internet directly. WiFi calling is charged here according to home rate, making it attractive in roaming.
Of course it can reach any phone, just like cell phones. While VoLTE doesn't necessarily rely on a data plan, as calls are billed differently, it's still uses "data". Cell phones have been moving away from traditional TDM/FDM networks for years. For example, the basic service today is UMTS, which is essentially GSM over packets, instead of TDM/FDM channels. VoLTE is VoIP encrypted by IPSec and carried on UDP. I have verified that with WiFi calling using Wireshark, to watch the WiFi connection. https://en.wikipedia.org/wiki/UMTS https://www.radio-electronics.com/info/cellulartelecomms/umts/umts-wcdma-net... https://www.pcworld.com/article/259471/voice_over_lte_explained_better_voice... https://www.radio-electronics.com/info/cellulartelecomms/lte-long-term-evolu... https://heim.ifi.uio.no/sjurtf/Sjur-Fredriksen-Security-in-LTE-and-VoLTE.pdf https://books.google.ca/books?id=AEozDwAAQBAJ&pg=PT417&lpg=PT417&dq=voice+over+lte+description+ipsec&source=bl&ots=P8UYxGQr0K&sig=EsUr9ew4dPSqluxSe0XDTOsc20Y&hl=en&sa=X&ved=2ahUKEwji3Y__3cTcAhWL5YMKHRsSBuM4ChDoATACegQIARAB#v=onepage&q=voice%20over%20lte%20description%20ipsec&f=false From http://www.oracle.com/us/industries/communications/wifi-calling-epdg-wp-2874... 2. The emergence of WiFi Calling An emerging solution is WiFi Calling (also known as Voice over WiFi). Like VoLTE, this is compliant with 3GPP standards and enabled by an IMS . Mobile operators can use this to ‘fill the gaps’ in VoLTE, while for non - cellular providers, it provides a way to offer wireless voice services without the need for an MVNO agreement. WiFi Calling is an extension of the 3GPP’s evolved packet c ore (EPC) architecture which allows any WiFi network to access the EPC via a gateway at the border between the public internet and the operator domain . The gateway is the evolved packet data gateway (e PDG) which is part of the 3GPP I - WLAN platform . The e PDG creates a secure IPsec tunnel from the EPC all the way to the device and anchors traffic in the packet gateway (PGW) , which means WiFi can be treated in the same way as a cellular RAN by the mobile core And there's much, much more that shows VoLTE is VoIP encrypted by IPSec, carried by UDP over IP. That IP can be via the cell network or WiFi/Internet and as I mentioned provides seamless transition between the two. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org