5G roadblock: labor

Michael Thomas mike at mtcc.com
Mon Dec 30 23:46:12 UTC 2019


On 12/30/19 3:34 PM, Christopher Morrow wrote:
> On Mon, Dec 30, 2019 at 6:09 PM Michael Thomas <mike at mtcc.com> wrote:
>>
>> On 12/30/19 2:46 PM, Brandon Martin wrote:
>>> On 12/30/19 5:42 PM, Michael Thomas wrote:
>>>> Oh, I didn't know that. Seems like it's a relatively new thing. Seems
>>>> like they went to a lot of trouble to essentially do what voip does.
>>>> Or maybe not? I've been poking around trying figure out what's going
>>>> on under the hood with wifi calling, and it seems like they're just
>>>> tunneling PSTN bits over the internet. If true, that's certainly a
>>>> quick and dirty hack. Maybe they're doing something similar for volte?
>>> My understanding is that VoLTE is signaled using SIP.  I don't know
>>> how the media moves.  I think they tried to avoid re-inventing the
>>> wheel. Most of the "phone" guys are slinging a lot of inter-network
>>> calls via IP these days, anyway.
>>
>> Yeah, maybe it really is RTP because iirc, VoLTE can use different
>> codecs. That would make some sense since a lot of those voice bits are
>> going to end up as RTP at some point. I can understand the wifi hack
>> since they may not have had the ability to directly deal with customer
>> facing RTP from the phones 5 years ago.
>>
>> Maybe my google-foo is really bad, but it's not been easy to get an
>> overview of what's going on under the hood for these. And I'd prefer to
>> avoid the 3GPP tar pit.
> I had thought the 'benefit' of LTE (specific to Voice) was a SIP UA
> was implemented at the handset for all 'voice' over the LTE network.
> (voice calls through your carrier - VoLTE)
>    https://en.wikipedia.org/wiki/Voice_over_LTE
I finally found something and it is indeed SIP/RTP over a LTE with some 
extra qos secret sauce. I have no idea what's going on differently in 
the MAC.

So we're definitely almost there. And that's a good thing.

Mike




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