🚀 go-pugleaf

Willy Lusti <wlusti@active.ch> writes:
> ich denke darueber moechten noch viel mehr leute was wissen - 

In case nobody from Swiss Telecom/Swisscom wants to reply (you can
always dial 113^H^H^H155-0-113 and ask for information), here are a
few words about the SwissWAN service, from my experiences with it at
SWITCH.  Standard disclaimers apply.

SwissWAN offers a VP bearer service with a CBR traffic contract with
optional usage profile.  That is, once you have a physical SwissWAN
connection, you order VPs (ATM Virtual Paths) with a given bandwidth
(PCR, Peak Cell Rate).  SWITCH currently has VPs with PCRs of 4, 8,
and 16 Mbps, but lower/higher/odder bandwidths are certainly
supported.  It would be interesting to know what the minimum/maximum
values and granularity are.

The usage profile allows you to save communication costs by reducing
bandwidth or turning off VPs altoghether during certain times of the
day or week.  We use this on some links in SWITCHlan, which are
disabled during off-peak hours.

An ATM CBR VP is really a lot like a (virtual) leased line(*) in that
the bandwidth on your contract is always fully available to you and
you always have to pay for it.

Compared with a "real" leased line, it is nice that you can have VPs
at every imaginable bandwidth.  For traditional leased lines there are
only a few bandwidths available (due to the way they are multiplexed).
Notably there's nothing between 2Mbps and 34Mbps.

Also, once you have a SwissWAN connection, you can add/remove VPs to
other SwissWAN-connected sites without any physical installation work.
And with a single ATM interface card, you can handle a many VPs.
There still is an installation prodecure and fee for each new
connection.

As for prices, I don't know any numbers, but a few notes:

There are initial and recurring costs for a SwissWAN endpoint at your
premises(**).  Our endpoints are 155Mbps single-mode fiber interfaces
- don't know if other bandwidths are available.  There are no
multimode connections as far as I know; this is a pity because
single-mode interfaces are more expensive and the connections more
delicate, but I can understand that Swiss Telecom wants to restrict
the choice of interfaces they have to support (keep spares for, etc.).

VP prices used to be independent of the distance between VP endpoints
- probably they still are.  They are not drastically different from
the prices for interregional leased lines of similar bandwidth as far
as I remember.

Another difference between Swiss Telecom's leased line and ATM
offerings is that SwissWAN seems to be managed more proactively.  When
there's a problem with a leased line, you have to call them, whereas
when there's a problem with ATM, they call you (they even notice when
you disconnect something from their switch for a couple of minutes :-)
In general, we found SwissWAN very reliable.  Almost all the problems
we had were with our own cabling and router hardware/firmware/software.

Alternatives

Alternatives to ATM would be Frame Relay and channelized E1/E3.
I think both of these are available from Swiss Telecom but we don't
have any experience with them.  Channelized E1 looks interesting for
providers who want to multiplex some low-speed leased lines on a
single interface in a "hub".

I would be very interested in hearing about other (forthcoming)
carriers' projects to offer ATM service in Switzerland.
-- 
Simon, speaking for himself
SWITCHlan NOC
(*) you can use ATM VPs to transport multiple VCs, and if you have
    your own ATM switches, you could even build something like an ATM
    VPN with signaling.  However, this is quite difficult with a CBR
    VP bearer service, because your switches would need to maintain
    the VPs' traffic contracts among switched VCs, which is hard.

(**) a SwissWAN endpoint consists of (a port in) an ATM switch.
    Swiss Telecom calls these "Service Muxes" (or "Simux" :-).
    E.g. In Zurich, SWITCH shares a Service Mux with ETHZ.  Both
    organisations have their own endpoints (port cards).  In
    Geneva the situation is similar between CERN and SWITCH.