[148037] in North American Network Operators' Group
Re: L3 consequences of WLAN offload in cellular networks (was -
daemon@ATHENA.MIT.EDU (Cameron Byrne)
Fri Dec 30 09:35:24 2011
In-Reply-To: <201112301415.32955.a.harrowell@gmail.com>
Date: Fri, 30 Dec 2011 06:34:32 -0800
From: Cameron Byrne <cb.list6@gmail.com>
To: Alexander Harrowell <a.harrowell@gmail.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Dec 30, 2011 9:16 AM, "Alexander Harrowell" <a.harrowell@gmail.com>
wrote:
>
> In the DHCP v6 thread, there was some discussion of
> mobility and its IP layer consequences. As various people
> pointed out, cellular networks basically handle this in the
> RAN (Radio Access Network) and therefore at layer 2,
> transparently (well, as much as things ever are) for IP
> purposes. It therefore shouldn't be a problem.
>
> However, as one contributor pointed out, more and more
> cellular operators are migrating traffic onto WLAN for
> various reasons, notably:
>
> 1) Spectrum - it's unlicensed, i.e. free
> 2) Capex - the equipment is cheaper
> 3) Capacity - it's a cheap way of providing high speed
> 4) Signalling load - it gets rid of the signalling traffic
> associated with detaching and attaching devices from the
> core network. This is especially important in view of some
> smartphones' behaviour.
>
> Of course much of the signalling is associated with the
> Mobility Management features, and getting rid of it by
> punting everything to WLAN implies that you lose the
> benefits of this.
>
> That suggests that if you're going to do this on a big
> scale you need to implement Mobile IP or else keep
> backhauling traffic from the WLAN access points to the
> cellular core network (GAN/Iu interface), which has obvious
> effects on the economics of the whole idea.
>
> Alternatively, you can work on the assumption that the WLAN
> is solely for nomadic use rather than true mobility, but a
> lot of devices will prefer the WLAN whenever possible.
>
> Thoughts/experiences?
>
>
The state of the industry is the support of nomadic mobility from cellular
to / from Wi-Fi , there is nearly no support of mobile IP that I have seen.
It is going more and more in this direction. At T-Mobile USA we have
evolved our wifi calling features from fully mobile UMA / GAN to non-mobile
IMS wifi calling.
Cb
>
> --
> The only thing worse than e-mail disclaimers...is people
> who send e-mail to lists complaining about them
On Dec 30, 2011 9:16 AM, "Alexander Harrowell" <a.harrowell@gmail.com>
wrote:
> In the DHCP v6 thread, there was some discussion of
> mobility and its IP layer consequences. As various people
> pointed out, cellular networks basically handle this in the
> RAN (Radio Access Network) and therefore at layer 2,
> transparently (well, as much as things ever are) for IP
> purposes. It therefore shouldn't be a problem.
>
> However, as one contributor pointed out, more and more
> cellular operators are migrating traffic onto WLAN for
> various reasons, notably:
>
> 1) Spectrum - it's unlicensed, i.e. free
> 2) Capex - the equipment is cheaper
> 3) Capacity - it's a cheap way of providing high speed
> 4) Signalling load - it gets rid of the signalling traffic
> associated with detaching and attaching devices from the
> core network. This is especially important in view of some
> smartphones' behaviour.
>
> Of course much of the signalling is associated with the
> Mobility Management features, and getting rid of it by
> punting everything to WLAN implies that you lose the
> benefits of this.
>
> That suggests that if you're going to do this on a big
> scale you need to implement Mobile IP or else keep
> backhauling traffic from the WLAN access points to the
> cellular core network (GAN/Iu interface), which has obvious
> effects on the economics of the whole idea.
>
> Alternatively, you can work on the assumption that the WLAN
> is solely for nomadic use rather than true mobility, but a
> lot of devices will prefer the WLAN whenever possible.
>
> Thoughts/experiences?
>
>
>
> --
> The only thing worse than e-mail disclaimers...is people
> who send e-mail to lists complaining about them
>
