Internet Traffic Management and Accounting at UNSW David Rees Senior Network Engineer

About UNSW Around 40,000 students & 5,000 staff Main campus at Kensington in Sydney’s Eastern Suburbs of Sydney); some small campuses within Sydney and several small WAN sites around NSW Several affiliated organisations such as NIDA, Garvan Institute, CCIA, Victor Change Cardiac Research Institute, NewSouth Global, Private Colleges etc

UNSW’s Network 2 x /16 IPv4 subnets (no NAT) 90,000 unique devices Redundant 10Gb/s links to AARNet & Internet (since Feb 2009) Data centres, most buildings and large WAN sites connected at 10Gb/s

Download Stats Downloaded 747.2TB in 2010 (267.2TB metered), peaking at 1.72Gb/s Mostly web traffic, not much R&E traffic

Wireless Network (UniWide) Upgraded wireless network in late 2007 and we decided to make it free with no quotas (subject to acceptable use policies) Much of growth in metered downloads can be attributed to the free, unlimited wireless network: wireless currently responsible for over half of Internet downloads No free wireless coverage in student accommodation areas

Copyright Infringement Receive around 1 or 2 copyright infringement notices per week, mostly for students on wireless network Penalties for network abuse include loss of access to the wireless network for up to one session; a formal disciplinary letter from the University and a fine of up to $1,000

Content Filtering We have the capability to filter web traffic using Blue Coat proxies but we don’t filter any traffic apart from shaping of P2P traffic on the wireless Decision taken at executive level not to filter anything Content filtering goes against the University ethos and there would be a large outcry if we did

Network Charging Models Student accommodation on campus (colleges) pay roughly $3 per GB for downloads (all traffic metered) Affiliated organisations (NIDA, Garvan Institute etc) are billed quarterly using a cost-recovery model which is based on a combination of connection charges ($42 per unique MAC address) and Internet downloads (off-net traffic only but off-peak is metered) Centrally funded faculties and business units are not charged but all network segments/VLANs are still measured as if they were, using the same billing system as the affiliated organisations Wireless network is free

UniWeb College Per-User Billing The student accommodation networks use the ‘UniWeb’ per-user billing system Pre-paid service based on Cisco Service Selection Gateway (SSG) integrated with a captive web portal for authentication Cost is approx $3 per GB downloaded The system was setup around 8 years ago and hasn’t really been touched since (same Sun server & same router still chugging along!)

Centurion IP Billing Network billing system for Affiliates is a 9 year old home- grown solution built by guys that left in 2003 Combination of connection charges and traffic charges gathered for every segment/VLAN on the network and then billed quarterly Only external customers/Affiliates are actually billed; vast majority is paid for centrally out of the Comms budget. System comprises basically three servers; one server for collecting data for the connection charges, one server for collecting data for the traffic charges and one server that runs the main database and reporting

Centurion IP Billing (cont.) Connection charges are based on the number of unique MAC addresses seen on a segment; as measured by a PERL script that runs every hour to grab the MAC address and ARP tables from key network devices Traffic charges are based on Netflow records from the primary border router. An attempt is made to only charge for off-net traffic but the list of on-net routes hasn’t been updated since 2003 and off-peak traffic is also metered Each quarter, a report is run which combines the data from the connection and traffic collectors and, where appropriate, bills are sent out to the owners of each network segment.

Future We have Cisco SCE’s which are currently just monitoring Internet traffic and shaping P2P on wireless We purchased TSA’s CAAB solution for telephony billing so we’ll probably buy the IP billing module for that and integrate it with the SCE’s to replace the college per- user billing system and implement quotas Low priority until the old systems break

Challenges Old billing systems are unmaintained, poorly documented and nobody really understands how they work Recently had to rewrite the MAC address collector to use SNMP instead of Expect scripts so we could implement AAA on network devices Ambiguous ‘ownership’ of legacy billing systems between Operations and Finance. May not be worth replacing the old billing systems if AARNet Excess charges go away and the proportion of metered traffic continues to fall

Off-Net Subscription Usage