FTTH Active vs Passive

Delian Delchev delian at promela.com
Wed Dec 2 12:17:06 CST 2009


Generally "Ethernet" itself support in the last years natively "Openaccess".

But first you need to answer to youself what type of Openness you want?

Open Access on Layer3 level? As it is made by the ADSL L3 LLU?
If so, then both Active and passive FTTH Ethernet are absolutley ready for
it. Every Service provider is a single VLAN, DHCP snooping, ARP snooping (to
enforce security) are enabled and that is. You can even do the same services
as the ADSL providers, you can buy (only for central place, for service
control, not for access) BRAS solution as Juniper MX or Ericsson SE1200 (or
Alcatel or even the currently slow performing Cisco) and to have radius
authentication per session and per vlan. You can even give to your service
provides Virtual Logical Router (with its own administrative control) in MX
or Logical Context (which is the same, but implemented in more scalable way)
into the Ericsson SE1200.
You can have integrated L3 Open Access solution from a vendors like Packet
Front, but their solution is expensive per subscriber (in large scale) and
performs well only on L3.

Open Access on Layer2 level? This is the absolutely pure Open Access you can
have. Pure Layer2 tunnels from the Service Provider to the subscriber's
port. Then the service provider can do whatever it wants and provide L3 and
L2 services in absolutely independent and transparent way.
Active Ethernet is ready for this today. You can do 802.1ac/ad (Double VLAN
Tagging) per port and have 16m combinations (ports) that you can transport
transparently to your service providers. You can do it with very expensive
equipment (as Cisco, Juniper, etc) or with even really cheap equipment (for
about 5$ per port) as well. Ethernet today have many interesting carrier
features supported as standards directly by IEEE. You can have security,
encryption, control, bandwidh control (even on HQ), filtering, pure
transparent transportation. The mac addresses and the VLAN IDs are not
limitation anymore for years. You have even Ethernet SNMP, PING, Traceroute,
service control. If you need some guides on this, I can tell you, but I
don't think is necessary to get deeper on that right now.

PON is relatively close to L2 open access. Most of the vendors are "almost
there" where 802.1ac/ad standard is. So here the situation is relativley the
same as in the active ethernet.

Delian


On Wed, Dec 2, 2009 at 7:45 PM, Alexander Harrowell
<a.harrowell at gmail.com>wrote:

> Another issue - how far does the technology support open
> access/infrastructure
> sharing/wholesaling? Not only are networks that get public funding likely
> to
> be expected to provide these, but there is evidence that they are important
> financially.
>
> Benoit Felten's presentation at eComm Europe suggested that the takerate
> and
> the presence of wholesale were the biggest sensitivities bearing on the pay
> off
> period for a FTTH deployment.
>



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