Improving slow response times

Are you experiencing delays with one of the Libraries Australia services? If so, you may find this guide helpful. It explains how and where problems affecting response times can occur with advice on what to do in each situation.

Libraries Australia is a complex set of systems and services hosted by the National Library of Australia. It is accessed over the Internet from different servers and ports, using different protocols, depending on the service you are using. This means that establishing the reason for slow response is not always easy.

There are 3 basic areas which can cause your response time to be slow:

  1. Libraries Australia itself
  2. The Internet
  3. Your local network

LA/Internet relationship

1. Libraries Australia

Libraries Australia consists of 4 modules:

  • Search
  • Cataloguing
  • Document Delivery
  • Administration

Under normal operating conditions Libraries Australia maintains a response time at an acceptable level (i.e. < 1minute). (Availability over a 12 month time frame is recorded in our Annual Reports).

If you are experiencing unacceptable response times contact the Help Desk to determine if there are any problems with Libraries Australia itself.

Significant problems (as well as planned outages) are posted to our discussion lists and latest news. Ensure you are subscribed to the discussion list and regularly check the news feed for updates.

If you consistently experience unacceptable response times in any of the 4 modules, and there are no problems with Libraries Australia itself, the cause may be the Internet, your organisation's connection to the Internet, or your local area network (LAN) environment.

2. The Internet

Data will not always travel the same route between your PC and Libraries Australia. The route - signified by the lines in the diagram above - may vary according to conditions in those parts of the Internet that your data must cross.

All data sent over the internet is sent in packets. Packets can be imagined as small parcels being passed from computer to computer.  These packets travel in a series of hops across a number of routers depending on the location of your PC/network. Bottlenecks may occur at one or more of the routers.  In some slow response times, one router may be overloaded for a short time. If one router consistently shows as a bottleneck in your connection with Libraries Australia your Internet Service provider (ISP) may be able to rectify this.

Two programs can be used to diagnose problems with your Internet connection by sending packets of information to a remote computer: Ping and Traceroute. These programs allow you to determine if a problem is in your Local Area Network (LAN), out on the Internet, or at the National Library.

To use Ping and Traceroute you will need a command prompt:

  • In Windows XP or below, click the Start button and select Run. Enter command or cmd. Click OK. A windows command prompt screen should appear.
  • In Windows Vista and above click the Windows button and type Command Prompt. Press Enter. A windows command prompt screen should appear.

Ping

Ping can test the speed of your connection, distance to target, and whether or not your connection is even up and running. It tells you how long a packet of data takes to travel from your computer to a specified host, and back.

To use Ping, type ping followed by a destination host name or IP address (e.g. for LA Search: host name = librariesaustralia.nla.gov.au or host IP address = 192.102.239.68).  You can also ping your own IP address.

If all 4 packets sent are received, then the connection is working fine. Any lost packets may indicate a slow connection.  If no packets are received, you'll see something like Destination Host unreachable or Request Timed Out.  This can indicate that your connection is not routing properly.

If your network has a Firewall or Proxy Server, then Ping may not be able to help.

Traceroute

Traceroute tracks the path that a packet takes from your computer to a destination address. It reports on the number of hops taken for the data to traverse the routers from the target website to your location, identifies the IP address of each router and lists the round trip time (in milliseconds) taken to arrive at each router.

Traceroute will aid in identifying where delays or bottlenecks may be occurring (e.g. in your local router, your regional connection, the Canberra regional network, or in the National Library itself).

To use traceroute, Windows users should use the command tracert, Mac users should use traceroute.

If your network has a Firewall or Proxy Server, then Traceroute may only reach the Firewall or Proxy server. As the reports from Traceroute are fairly complex, you may need assistance from your local IT staff to interpret them.

If you think you are having problems with your Internet connection, contact your ISP or ask your IT staff to assist.

Traceroute reports that show one hop taking much longer than others in the path through the Internet may indicate a bottleneck at that point.

Factors affecting Traceroute results

The times reported by a Traceroute can be affected by a number of factors, which can distort the results. They include:

  • Routers may use a different priority when responding to trace packets, which can result in different response times which are not experienced by normal traffic.
  • Requests are not sent to all locations at the same time, so the level of traffic may have changed between readings. The times reported are the round trip to that location.
  • Delays can also be introduced by the need to fragment packets in some circumstances. This will not affect your standard Traceroute measure, but it may affect your Libraries Australia traffic.
  • Packets may not be travelling along the same path in both directions, or even every time in the same direction.

To minimise the effect of these factors, a number of Traceroutes should be run, preferably over a period of at least one week, to obtain a representative indication of where the problem lies. This may
also eliminate the possibility that a temporary problem at one point in the connection is the cause of your slow response time.

Recommendations

If a bottleneck is discovered and the bottleneck occurs in the Internet or at your point of entry into the Internet, the following actions may help to improve response time:

  • If you are using a dial-up connection via a modem, check that your modem is connecting to your ISP at the modem's designated speed. If the effective speed of your link is lower than it should be, discuss the problem with your ISP and try different types of modems.
  • Some Libraries Australia subscribers may find a cable modem or ADSL connection provides improved response time. These devices allow high-speed data access (such as to the Internet) via a cable network or upgraded telephone network. These services are not available in all parts of Australia.
  • Obtain measurements of the level of utilisation and reliability of your Internet access link during peak periods from your ISP or network manager. You should ensure that the report covers the level of utilisation during normal working hours, and excludes the level of utilisation outside business hours. If the utilisation level is high it may be necessary to add more bandwidth to carry the load.
  • Consider dedicating one or more links to Libraries Australia traffic, to separate it from other Internet traffic. i.e. Consider over-provisioning the access link bandwidth, in order to use a higher speed link which will reduce transmission delays, and reduce the effects of congestion from other Internet traffic. For Libraries Australia traffic alone, however, there is a diminishing improvement in response times with link speeds above 64 Kbps. When choosing an ISP select one which can demonstrate the smallest round-trip times to the Nnode in Canberra. The gateway address is abngw.nla.gov.au (202.6.91.20) and Ping can help identify the round trip times. You should run several Ping tests to ensure a representative result.  Talk to your IT staff about addressing the bottleneck.

3. Your Local Network

The configuration of your Local Area Network (LAN) and the level of traffic it carries may affect both incoming and outgoing Libraries Australia response times.  The transmission speed or performance of your local network will affect your overall communication with Libraries Australia. If the local network's processing speed is slower than your external Internet access, you will experience response time delays locally. It is important to check that there are no delays within your local network. The Ping and Traceroute tools can help to identify if your response time delays are occurring in your LAN.

Impacts from security measures

Your organisation will have security measures in place to protect your own network from security violations. Security policy and the consequent level of filtering will be determined by each organisation according to its own security requirements and assessment of possible risk. Devices used to implement security policies include Firewalls and Proxies.

Firewalls and Proxies operate by applying filters to all Internet traffic. For instance, they can be set up to filter out communications containing specified protocols or coming from certain Internet sites. This has occurred for some Libraries Australia Search subscribers whose firewalls do not permit access to sites that include JavaScript. Other Libraries Australia subscribers have experienced firewall exclusion for activities using the Libraries Australia Cataloguing Client.

Check your firewall policy. Your firewall maybe blocking access to some components of Libraries Australia.

Standard and non-standard ports

Libraries Australia uses standard protocols and ports to minimise the effect of security constraints on connecting to our services (see our Service connection details).  However, in order to use the Libraries Australia Cataloguing Client, certain TCP ports (i.e. 1521) need to be enabled on firewalls in order to access the cataloguing server.

Some restrictive firewall configurations will not allow cataloguing traffic through port 1521. In response to requests to allow for an additional port to be made available on the Libraries Australia Cataloguing Server, port 11521 has also been configured to accept connections.

Does your firewall allow access through port 1521? If not,you will need to configure port 11521 to accept connections from the Libraries Australia Cataloguing Server instead – ask your IT staff to assist you with this.

Further Assistance

Where the steps above identify causes of slow response times outside the control of the National Library, please contact the Libraries Australia helpdesk.