Abstract

During the last years, MultiProtocol Label Switching (MPLS) has been
deployed by most large Service Providers (SP). The main driver
for MPLS deployment is the ability to provide new services
with stringent Service Level Agreements (SLAs) such as layer-2 and layer-3
Virtual Private Networks (VPNs) as well as Voice and Video over IP.
Most of these services are already deployed inside single SP networks.
However, customers now require world-wide VPN and VoIP services.
Therefore, SPs need to collaborate to offer these services across
multiple SP networks.
Inside a single SP network, each node usually knows the complete topology
of the network with the load and delay of all the links. Based on this
information, each router is able to compute constrained paths toward any
other router inside the SP network. Then, it can establish a connection and
reserve resources along the computed path with the Resource reSerVation
Protocol (RSVP-TE). However, when services with stringent requirements must
cross multiple SP networks the computation of the path
becomes a problem. Routers in different SP networks exchange routing
information by using the Border Gateway Protocol (BGP). BGP provides
reachability information. It does not distribute complete topology, delay
and bandwidth information. One way to provide guaranteed services crossing
different SPs is to delegate the computation of the paths to a Path
Computation Element (PCE) that learns the topology of the different SPs.
However, this requires that SPs reveal information that they usually consider
confidential, their topology.
In this thesis, we perform active measurements to show the difficulty to
engineer the interdomain traffic with BGP. MPLS together with
RSVP-TE provide much more control on the traffic. We define extensions
to RSVP-TE for the protection of inter-AS MPLS paths. The aim is to be able
to provide the same service guarantees as inside a domain while keeping
the internal topology of SPs confidential, as required by SPs. We propose
and evaluate distributed techniques relying on PCEs for the computation of
interdomain constrained paths respecting the latter confidentiality
requirement.