May 2006
Compiled by Charles Spurgeon
ITS Networking Services
Contents:
- Introduction
- Internet Traffic
- Active IP and MAC Addresses
- UTnet Devices, Ports, Routed Interfaces, Servers and Dialup Lines
- Assigned IP Addresses
- Domain Name Service Queries
- Active IP Subnets
- Core and Backbone Switching System
i. Introduction
UTnet, the campus computer network, supports teaching, research, and the administration and operation of The University of Texas at Austin with high-performance networking that is also designed to provide high reliability and manageability.
This UTnet status report provides a brief look at some statistics for UTnet, and documents the traffic rates, the current size of the network and the host population, and provides some data on the growth of the system.
a. Scope of UTnet
UTnet serves the University of Texas at Austin, which has an enrollment of approximately 50,000 students as well as 3,000 faculty and 18,000 staff. The University has a $1.3 billion annual budget, with annual research funding that exceeds $417 million across more than 90 research units.
There are 16 colleges at UT, as well as 7 museums and 17 libraries. The main UT Austin and Pickle Research Center (PRC) campuses include 188 buildings, with a UTnet presence in the vast majority of them. UTnet also serves a number of external sites located around the city of Austin. All told, the campus network serves a combined total of roughly 200 buildings and sites.
b. Brief Summary of UTnet Status
The UTnet campus network system continues to grow rapidly in terms of both the size of the network and its usage by the campus community. The number of computers and users continues to increase, and the traffic carried over the UTnet core routers has increased by 70 percent in the last year. Traffic carried between the campus network and the Internet has increased by roughly 12 percent.
1. Wireless Network
The wireless network system continues to grow at extremely rapid rates; currently there are more than 1,500 wireless network access points. Assuming that this growth rate continues, we can expect all of campus to be covered with wireless networking signals before too long.
2. Major UTnet Upgrades
During the May and August 2006 maintenance windows, the main campus core routers will be upgraded to improve their performance. These upgrades will include new chassis and power supply installations to support both higher density and higher power network modules. New 10 Gigabit Ethernet modules will be installed, doubling the number of 10 Gigabit Ethernet ports available for connections to buildings on the Main UT campus.
The wireless network system will also be upgraded during the summer 2006 maintenance window. This upgrade will continue to support the rapid growth of the wireless network by doubling the number of wireless traffic controllers and increasing their capacity. Ongoing active evaluation and development of new wireless technologies will also ensure the continuing evolution of the wireless network.
I. Internet Traffic
The traffic rates shown in this section are in megabits per second (Mbps) and are derived from long term averages that include approximately one month of data. The actual peak hourly rates seen on the network are significantly higher than these numbers reflect, and the five- minute and one-second peak bit rates can be much higher. The long term averages shown below are used for multi-year percentage growth comparisons. Network traffic planning uses different values and is based on taking the 95th percentile for busy day traffic rates, which measured 346 Mbps inbound and 182 Mbps outbound for spring 2006.
Average UTnet Traffic Rates, Input and Output in Megabits per second (Mbps) |
||||
|
Average Input Rate (Mbps) |
Increase Over Prior Year |
Average Output Rate (Mbps) |
Increase Over Prior Year |
March 20-April 20, 2006 |
192.5 Mbps |
11.9% increase over 2005 |
152.0 Mbps |
6.0% increase over 2005 |
March 20-April 20, 2005 |
172.02 Mbps |
5.4% increase over 2004 |
143.39 Mbps |
37.4% increase over 2004 |
April 2004 |
163.20 Mbps |
24.7% increase over 2003 |
104.36 Mbps |
22.9% increase over 2003 |
April 2003 |
130.87 Mbps |
|
84.90 Mbps |
|
A. UTnet Dual Fiber-Optic Core Traffic
The UTnet main campus core network is composed of a dual fiber-optic cabling system that connects each building router to two high-performance Cisco Catalyst routers located in the network operations center (NOC).
The dual fiber-optic core statistics shown here account only for traffic seen by the two NOC routers. This does not account for any traffic that was sent between network segments located entirely within buildings, or located in the buildings supported by any of the core routers other than the two fiber-optic star routers.
In other words, this is only traffic that had to transit the dual fiber-optic star system to reach its destination. This traffic includes all traffic to and from the external Internet and Internet2 research networks.
The two fiber-optic core routers recorded the following traffic counts over a period of 14 weeks, 2 days and 8 hours (since they were last reloaded).
| Time Period | Number of Bytes | Number of Bits |
|---|---|---|
| 14 weeks, 2 days, 8 hours (144,480 total minutes) |
827,675,137,433,405 Bytes |
763,819,801.98 bits per second |
Switched Bytes Long-term Average Rates:
5.72 billion bytes per minute
95.47 million bytes per second
763,819,801.98 bits per second or 763.81 Mbps
Compared with the 2005 rate of 3.34 gigabytes per minute, this represents a 71 percent increase.
| Time Period | Number of Packets |
|---|---|
| 14 weeks, 2 days, 8 hours | 1,202,911,713,092 |
Switched Packet Long-term Average Rate:
8,325,800.89 packets per minute
138,763.34 packets per second continual average rate
This is a 18.89 increase in average packets per second over 2005.
II. Active IP and MAC Addresses
An Internet Protocol (IP) address is required for communication over the network. The IP address is either statically assigned to a device and manually configured into it, or dynamically acquired by the device via the Dynamic Host Configuration Protocol (DHCP).
There is a separate medium access controller (MAC) address, also known as a "hardware address," that is configured into each Ethernet and wireless interface by the manufacturer. The MAC address is considered to be permanently assigned to the interface.
Various management servers in the UTnet management system track the IP and MAC addresses seen in use on UTnet. The combination of IP and MAC address information, for example, allows the UTnet management system to track computers by their address usage, and to locate the switch port to which a given computer may be connected.
This data represents a snapshot of the number of active computers seen on UTnet.
A. IP and MAC Address Statistics Excluding the Public Networks (Wired/Wireless)
The following sample represents the number of IP and MAC addresses recorded in the UTnet database over the last 170 days prior to April 17, 2006; these numbers exclude addresses from the wired and wireless Public Network Authentication (PNA) system.
Year |
Time Period |
Ending Date |
Distinct IP Addresses |
Distinct MAC Addresses |
2006 |
170 days |
April 17, 2006 |
49,077 |
48,998 |
2005 |
90 days |
April 10, 2005 |
58,760 |
50,266 |
2004 |
180 days |
May 14, 2004 |
58,804 |
54,693 |
Analysis of a separate monitoring system based on Cisco Netflow data found: 68,053 unique IP addresses. This shows an increase when compared with 58,824 unique IP addresses in 2005, and 61,697 unique IP addresses in 2004. The Netflow addresses were seen in traffic crossing the UTnet core routing system over the last few weeks leading up to April 18, 2006. These include both wired and wireless/public ports.
B. IP and MAC Statistics for the Public Networks (Wired/Wireless)
The wired Ethernet ports and wireless access points (WAPs) that make up the Public Network on UTnet are connected through a set of Public Network Authentication routers that keep their own statistics. These statistics indicate a 36 percent growth in the number of users of the wireless system.
Year |
Time Period |
Ending Date |
Unique IP Addresses |
Unique MAC Addresses |
2006 |
180 days |
April 18, 2006 |
13,109 |
42,292 |
2005 |
90 days |
April 10, 2005 |
10,202 |
25.893 |
2004 |
90 days |
May 14, 2004 |
6,981 |
17,249 |
The PNA system also recorded the following information about users:
Unique Users on the Public Network |
|||||
Year |
Time Period |
Ending Date |
Number of Unique Users – Wired |
Number of Unique Users – Wireless |
Total Number of Unique Users |
2006 |
90 days |
April 26, 2006 |
3,650 |
34,941 |
35,702 |
2005 |
90 days |
April 10, 2005 |
7,184 |
25,577 |
27,332 |
2004 |
90 days |
May 14, 2004 |
5,855 |
15,176 |
17,150 |
1. Wireless Access Points and Users
The total number of wireless access points continues to grow at a rapid rate:
Wireless Access Points Growth Rate |
||
Time Period |
Total Number of Wireless Access Points |
Increase over Prior Year |
April 2006 |
1,504 |
53.4% increase over 2005 |
April 2005 |
980 |
100% increase over 2004 |
April 2004 |
490 |
55% increase over 2003 |
April 2003 |
316 |
|
There has also been a steady increase in the total number of unique wireless users:
Total Number of Unique Users - Wireless |
|
Time Period |
Total Number of Unique Users - Wireless |
April 2006 |
34,941 |
April 2005 |
25,577 |
May 2004 |
15,176 |
May 2003 |
3,000 (approximate) |
The number of simultaneous users on both the wired and wireless PNA reflects these increases as well:
Approximate Peak Number of Simultaneous Users on the PNA |
|
Time Period |
Total Number of Simultaneous Users - Wireless |
April 2006 |
3,900 |
April 2005 |
2,100 |
May 2004 |
1,500 |
May 2003 |
700 |
Note: The number of unique IP addresses varies from the number of MAC addresses since a given machine with a MAC address may acquire multiple different IP addresses over time. On the PNA system the set of IP addresses are all assigned dynamically, with short IP address lease times leading to a high rate of IP address reuse by the total set of machines being served. Therefore, the number of IP addresses seen is considerably smaller than the number of MAC addresses. In this case, the number of unique MAC addresses is a better indicator of the total number of computers using the system.
III. UTnet Devices, Ports, Routed Interfaces, Servers and Dialup Lines
The UTnet network management system is actively managing over 3,788 network devices. This set of devices includes 2,276 switches and 1,512 wireless access points. It also provides over 84,792 Ethernet interfaces, also called ports. Adding in another 4,538 ports in use at two large sites that are not in the UTnet management tools gives us a total of roughly 89,150 ports.
We estimate that there may be approximately 5% more switches and ports connected to UTnet that are not being managed in the UTnet management system, resulting in a total of roughly 3,977 devices supporting approximately 93,607 interfaces or ports.
A. Routers and Routed Interfaces
There are 81 Cisco routers (routing packets at Layer 3) supporting a total of 2,134 routed subnets.
B. Network Servers
There are approximately 70 network server computers used to provide critically important network services (DNS, DHCP, etc), as well as network management and monitoring functions.
C. Telesys
There is a total carrier capacity of approximately 500 Telesys dialup lines supported in two Telesys servers, with usage of the dialup lines continuing to decline. Connection rates in April 2006 hover around a peak of 200 simultaneous connections.
IV. Assigned IP Addresses
The UTnet domain name server files contain the IP addresses for which symbolic names have been assigned (e.g., "www.utexas.edu"). In the past this set of name assignments provided a roughly accurate count of the number of computers using the campus network, however this count is no longer an accurate indicator of the number of hosts on the network. Currently, many IP addresses are pre-assigned for network management purposes and to provide a large address pool for use in dynamic address assignment. The most accurate host counts are found in the section Active IP Addresses.
A. Total Number of Assigned IP Addresses
There are a total of approximately 113,023 IP addresses assigned and available for use on UTnet, including 29,175 dynamic host configuration protocol (DHCP) addresses.
Total Number of Assigned IP Addresses by Date, with Rate of Increase |
||
Date |
Number of IP Addresses |
Rate of Increase |
April 2006 |
113,023 |
30.8% increase over April 2005 (~12 months) |
April 2005 |
86,361 |
11.1% increase over May 2004 (~11 months) |
May 2004 |
77,677 |
7.3% increase over March 2003 (~14 months) |
March 2003 |
72,347 |
36.8% increase over April 2002 (~11 months) |
April 2002 |
52,872 |
10.9% increase over April 2001 (~12 months) |
April 25, 2001 |
47,655 |
11.2% increase over Sept 2000 (~7 months) |
September 5, 2000 |
42,842 |
18.7% increase over May 1999 (~16 months) |
May 14, 1999 |
36,074 |
4.6% increase over Nov 1998 (~6 months) |
November 23, 1998 |
34,501 |
2.5% increase over May 1998 (~7 months) |
May 1, 1998 |
33,653 |
7.2% increase over Nov 1997 (~6 months) |
November 4, 1997 |
31,367 |
38.6% increase over Sept 1996 (~13 months) |
September 26, 1996 |
22,629 |
38% increase over Nov 1995 (~10 months) |
November 10, 1995 |
16,300 |
|
October 6, 1993 |
7,244 |
|
June 13, 1990 |
711 |
|
B. DHCP Addresses
Included in the count of IP addresses assigned in the globally routable space are entries with "dhcp" in the name, indicating that the address is used for dynamic host configuration outside of ResNet.
Total Number of DHCP Addresses by Date, with Rate of Increase |
||
Date |
Number of DHCP Addresses |
Rate of Increase |
April 2006 |
29,175 |
9.8% increase over April 2005 (~12 months) |
April 2005 |
26,559 |
15.7% increase over May 2004 (~11 months) |
May 2004 |
22,950 |
2.6% increase over March 2003 (~14 months) |
March 2003 |
22,356 |
25.7% increase over April 2002 (~11 months) |
April 2002 |
17,772 |
42.4% increase over April 2001 (~12 months) |
April 25, 2001 |
11,993 |
42.4% increase over Sept 2000 (~7 months) |
September 5, 2000 |
8,422 |
103.5% increase over May 1999 (~16 months) |
May 14, 1999 |
4,138 |
29.7% increase over Nov 1998 (~6 months) |
November 23, 1998 |
3,190 |
24.1% increase over May 1998 (~7 months) |
May 1, 1998 |
2,569 |
45.3% increase over Nov 1997 (~6 months) |
November 4, 1997 |
1,768 |
|
V. Domain Name Service Queries
One of the most critically important services on UTnet is the domain name service (DNS). This is the service that translates names (e.g., www.utexas.edu) into the IP addresses that computers use to send packets over the campus network and the worldwide Internet.
When you type a domain name or surf to a Web URL, a DNS query is sent to the UTnet DNS servers to look up the destination address. In response, the DNS servers provide your computer with the IP address needed to initiate packet communications with the destination that you have entered.
ITS Networking operates multiple domain name servers in a resilient configuration designed to make the campus DNS service as highly available as possible.
A. DNS Traffic Statistics
The following statistics are for all name servers combined.
Morning Busy Period |
||
Year |
Queries Per Second |
Increase Over Prior Year |
2006 |
577 |
21.9% |
2005 |
473 |
|
Afternoon Busy Period |
||
Year |
Queries Per Second |
Increase Over Prior Year |
2006 |
779 |
19.6% |
2005 |
651 |
|
Total number of queries on an average business day |
||
Year |
Queries Per Second, Daily Average |
Total |
2006 |
757.94 |
65,486,053 |
2005 |
182.30 |
15,750,944 |
VI. Active IP Subnets
Each network segment on UTnet supports a block of IP addresses. These network segments, also known as IP subnets, are used to direct the flow of traffic over the UTnet system. New subnets are added to support new buildings and organizations and to provide increased capacity for existing buildings and organizations.
The numbers provided here include subnets currently being used to deliver packets. In other words, these are subnets that are active in the campus routing tables.
The number of UTnet subnets has increased by 14.8% over 2005.
Number of UTnet Active IP Subnets by Date |
||
Date |
Number of Subnets |
Rate of Increase |
April 2006 |
2,131 |
14.8% increase over 2005 |
April 2005 |
1,856 |
16.2% increase over 2004 |
May 2004 |
1,597 |
14.6% increase over 2003 |
March 2003 |
1,393 |
20.8% increase over 2002 |
April 2002 |
1,153 |
35.9% increase over 2001 |
April 25, 2001 |
848 |
14.2% increase over 2000 |
September 5, 2000 |
742 |
|
May 14, 1999 |
630 |
|
November 23, 1998 |
598 |
|
May 1, 1998 |
566 |
|
November 4, 1997 |
550 |
|
September 26, 1996 |
375 |
|
November 10, 1995 |
304 |
|
July 21, 1995 |
266 |
|
September 9, 1994 |
214 |
|
June 15, 1990 |
77 |
|
VII. Core and Backbone Switching System
The core routers and the backbone routers and switches move packets between IP subnets and provide inter-building IP packet switching. These routers and switches direct the flow of traffic through the UTnet system, based on the IP address and the subnet to which the address belongs.
Core Routers and Switches in Main Campus and PRC NOC |
|
Equipment |
Device |
Core Routers |
9 |
Dual Backbone Routers and Switches |
|
Equipment |
Device |
Backbone Routers |
63 |
Backbone Switches |
12 |
Point of Presence (PoP) Routers and Switches |
|
Equipment |
Device |
PoP Routers |
13 |
PoP Switches |
70 |
Grand total of core, backbone and PoP routers and switches: 167 (Note that there are a number of backbone locations that have both a switch and a router.)
A. Connected Buildings and Sites
The total number of buildings and sites with a UTnet point of presence is currently 153.
There are approximately 188 buildings in the campus list of buildings for the main campus and PRC campus, and most of them have some sort of network presence.
The number of UTnet points of presence is not that same as the number of buildings, however, since the 188 building names include a number of residence hall lounges (included as part of residential buildings), storage buildings, etc.
B. Number of Connections and Speeds
The connection between the main campus and the PRC campus was upgraded to 10 Gigabit Ethernet in 2005. This connection travels over the fiber optic Greater Austin Area Telecommunications Network (GAATN).
The majority of the backbone and PoP connections on the main and PRC campuses are based on 1 Gigabit Ethernet, although there are several sites on the main campus which have a 10 Gigabit Ethernet connection to the NOC over the dual fiber optic backbone system.
Connections to sites |
||
Speed |
Quantity in 2006 |
Previous Year Quantity |
10 Gigabit Ethernet |
9 |
7 |
1 Gigabit Ethernet |
155 |
120 |
100 Megabit Ethernet |
47 |
52 |
1.5 Megabit Serial |
10 |
10 |
TOTAL |
221 |
189 |
Note: This is a count of total connections to sites and excludes connections used to link the core equipment to each other and to the UTnet border router.
