Re: Ethernet interface in a TDM device: FSC, TDM, or L2SC?

[Dimitri.Papadimitriou@alcatel.be]

hi - 

it can't be FSC as you don't switch in the spatial domain (FSC is for 
inst. used in the case of fiber distribution frames)

in your case your interface knows about processing payload of the TDM LSP, 
hence the point is if you put such i/f  back to back 

o) do you switch the STS -> TDM LSP with TDM encoding and TDM ST 

o) do you switch the whole Ethernet packet flow from port-to-port (no 
granularity from the Ethernet header info) -> Ethernet LSP with TDM 
Encoding and L2SC 

ps: if you take such flow from another interface and have limited capacity 
i suggest you take a look at the mln/mln solution doc where you can link 
such capacities

much thanks,
- dimitri.





Freek Dijkstra <fdijkstr@science.uva.nl>
Sent by: owner-ccamp@ops.ietf.org
17/07/2006 11:25
 
        To:     ccamp@ops.ietf.org
        cc: 
        Subject:        Ethernet interface in a TDM device: FSC, TDM, or 
L2SC?


Hi,

Another question.

I have a SONET cross connect. That is, a TDM device.
Most of the interfaces are TDM switch capable interfaces, which known
only about TDM encoding.

However, one of the interfaces of this devices knows about Ethernet
encoding, and is capable of taking the Ethernet packets and embed them
in a couple of STS channels (e.g. STC-24c or STS-3c-7v).

My question: what is the switching capability of this device?

It's not a L2SC, since it does not make decisions based on the MAC
addresses. I'm inclined to think it is also not a TDM switch capable
interface, since it does not switch based on time slots. All it does is
embed all data it encounters on the fiber. So it seems to me that this
interface is a Fiber-Switch capable (FSC) interface with Ethernet
encoding, despite that it is in a "TDM device".

Am I correct here?

Regards,
Freek