[192791] in North American Network Operators' Group
Re: Voice channels (FTTH, DOCSIS, VoLTE)
daemon@ATHENA.MIT.EDU (joel jaeggli)
Mon Nov 21 15:18:07 2016
X-Original-To: Nanog@nanog.org
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
From: joel jaeggli <joelja@bogus.com>
Date: Mon, 21 Nov 2016 12:18:01 -0800
In-Reply-To: <58334749.9080309@vaxination.ca>
Cc: "Nanog@nanog.org" <Nanog@nanog.org>
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From: joel jaeggli <joelja@bogus.com>
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
Cc: "Nanog@nanog.org" <Nanog@nanog.org>
Message-ID: <aa76117a-0371-3334-f682-37ee37eaba7a@bogus.com>
Subject: Re: Voice channels (FTTH, DOCSIS, VoLTE)
References: <58329B31.3070806@vaxination.ca>
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On 11/21/16 11:13 AM, Jean-Francois Mezei wrote:
> On 2016-11-21 02:53, Mikael Abrahamsson wrote:
>
>> Typically it travels on another "bearer" compared to Internet traffic.=
>>
>> http://blog.3g4g.co.uk/2013/08/volte-bearers.html
>>
>> Think of bearers as "tunnels" between the mobile core network and the =
>> device.=20
> Many thanks for the pointer. The fact that VoLTE has its own dedicated
> APN explains things.
>
> I am however a bit confused on the "bearer" term.
>
> Say a carrier has spectrum in 700Mhz bands A and B each 5mhz in each
> direction, bonded together as a single 10mhz (each way) channel.
>
> The docunment states:
> "R.92 requires the use of a particular set of radio bearers"
the radio bearers described are are the signaling radio bearers. their
existence is independent of of the link/mac layer configuration. The mac
layer layer (e-utra) exists below the l2 bearers.
https://en.wikipedia.org/wiki/E-UTRA
> Does this mean that a bearer is given specific spectrum within a block
> (such as a dedicated colour on a fibre) or that it is just given
> dedicated capacity on the single data channel formed by LTE compressing=
> all of the spectrum into one big channel ?
>
> I though I understood the concept when the name "tunnel" had been
> mentioned because I understand that a handset estabishes a "hopping"
> tunnel with local IP which changes as you move from tower to tower, but=
> the tunnel itself maintains a permanent IP connection that remains
> unchanged as you move from tower to tower. In such a concept, I could
> understand each tunnel (one to the data APN, one to the IMS/VoLTE APN)
> having bandwidth allocations.
these are URBs they are terminated between the UE and the P-GW
> But when the text brought up "radio bearer", I got confused again sicne=
> radio implies breaking the spectrum apart, which would reduce LTE
> compression efficiency.
SRB and URB are the l2 presentation of the tunnels established for user
and signaling traffic.
>
>
>
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