I keep hear of Frame-Relay and ATM signaling that is
going to happen in large providers MPLS cores. That's right,
your "safe" TDM based services, will be transported over
someones IP backbone first.
This means if they don't protect their IP network, the TDM
services could fail. These types of CES services are not
just limited to Frame and ATM.
(Did anyone with frame/atm/vpn services from Level3
experience the same outage?)
We use Level3 for IP transit and transport (both DS-3 and Ethernet over
MPLS (via Martini)) all over the country. As with everyone else, we saw
the problems with the transit traffic out of SJC and ATL. However, our
transport services were not affected at all by the problems. In fact, I
just ended up sending my Level3-SJC bound traffic to LAX via Level3
which was going through the same equipment as the transit traffic which
was having problems.
From this, it can be deduced that reducing unneccessary
system complexity and shortening the strings of pearls that
make up the system contribute to better availablity and
resiliency of the system. Diversity works both ways in this
equation. It lessens the probablity of same failure hitting
majority of your boxes but at the same time increases the
knowledge needed to understand and maintain the whole system.
I would vote for the KISS principle if in doubt.
I agree. Granted the string of pearls is always going to be pretty
long, but there are definitely is a trend from what I have seen with
customers to make the string longer than it needs to be.
Sean P. Crandall
VP Engineering Operations
MegaPath Networks Inc.
6691 Owens Drive
Pleasanton, CA 94588
(925) 201-2530 (office)
(925) 201-2550 (fax)