Software for Scalable Admission Control
We implemented the Egress Admission Control algorithm on a
testbed consisting of seven PCs running FreeBSD v3.2 as depicted
below. Please refer to the paper Design and
Implementation of Scalable Admission Control for detailed
information about experiments and results.
Our software implementation includes four modules:
- Timestamping. To communicate packet arrival
time at the ingress node (router A in the above picture) to the egress
node (router C), we first use NTP synchronize the clocks of the edge
routers. In this module, we modified the FreeBSD v3.2 kernel to insert timestamp
into fields of the IP header at the ingress node.
- Traffic Generation. This module generates Pareto
on/off flows. Before each flow is established, an RSVP signalling
message is generated to request admission by the egress node.
- Traffic Measurement. At the egress node (router
C), we capture the timestamp inserted at the ingress node and
calculate the path service envelope based on that. In this module, we
modified tcpdump to
capture packet information.
- Admission Control. We modified the RSVP v4.2a4 daemon to
call our egress admission control program upon receipt of a new
Available downloads for egress admission control are
Please contact pyuan At rice dot edu
for testbed questions/comments and
akrishna at bayou dot uh dot edu
for simulation questions/comments.