Tieline Help Desk

The following 10 tips are provided to help obtain the best possible IP connection between two codecs, without paying for QoS (Quality of Service). Note: Please ensure you select the correct country setting when creating 3G profiles using Toolbox.

1)  Always use the best quality Internet Service Provider (ISP).  Tier 1 service providers are best as their infrastructure actually makes up the Internet ‘backbone’. Wikipedia lists the major service providers that make up the Internet backbone at: http://en.wikipedia.org/wiki/Internet_backbone. In Australia Telstra is equivalent to one of these service providers.

2)  You will get the best quality connection if both the local (studio) and remote codecs use the same Internet service provider. This can substantially increase reliability, audio bandwidth and reduce audio delay. Using the same service provider nationally can give better results than using different local service providers.  This is especially true if one of the service providers is a cheap, low-end domestic service provider, which buys its bandwidth from other ISPs. Second and third tier providers sublease bandwidth from first tier providers and can result in connection reliability issues due to multiple switch hops. We also highly recommend using First Tier ISPs if connecting two codecs in different countries.

3)  Sign up for a business plan that provides better performance than domestic or residential plans. Business plans typically have a fixed data limit per month with an additional cost for data beyond that limit. In addition, Service Level Agreements (SLA) will often provide better support and response times in the event of a connection failure. Domestic plans are often speed-limited or “shaped” when usage exceeds a predefined limit.  These plans are cheap but they are dangerous for streaming broadcast audio. 

4)  Ensure that the speed of the connection for both codecs is adequate for the job. The minimum upload speed recommended is 256 kbps for a studio codec and 64 kbps for a field unit connection.

5)  Use good quality equipment to connect your codecs to the Internet. (Tieline successfully uses Cisco®[1]switching and routing equipment.):

1. If you are using a DSL or ADSL connection make sure you purchase a high quality modem that can easily meet your speed requirements. This is especially important if you are over 4 kms from an exchange.
2. If you have multiple codecs connected to a local area network (LAN) please ensure that your network infrastructure is designed for media streaming and not domestic usage. Tieline has tested several cheap 8-port switches that lose more packets between local computers than an international IP connection between Australia and the USA.

Please Note: You should be able to stream audio between two codecs on your LAN and get ‘link quality’ readings of L99R99. If you see anything less than this then you should get a network engineer to investigate the issue.

If using a wireless connection ensure that the antenna signal strength received is strong. The type of antenna used and the amount of output gain also affects connection quality.

• If you are using a 3G phone please make sure the battery is fully charged and that you are close to a cell-phone base station.

6) Once your Internet connection is installed at the studio check that the connection performance is approximately what you ordered and are paying for.  A connection can perform below advertised bit rates if:

• There is an error in ISP configuration;
• There is an error in modem configuration;
• There is a poor quality line between the studio and the exchange;
• There are too may phones or faxes connected to the phone line; or
• Line filters have been connected incorrectly.

You can test the Internet connection speed by connecting a PC to the Internet and using http://www.speedtest.net/index.php. If the bandwidth detected is low then something is wrong. Get it fixed before going live!

7)  Use a dedicated DSL/ADSL line for your codecs. Do not share a link with PCs or company networks. The only exception to this rule is if an organisation has network equipment and engineers that can implement and manage quality of service (QoS) on its network.

8)  Use UDP as the preferred audio transport protocol. TCP generally results in lower bitrates and random drop-outs of audio over the Internet. Only use TCP if UDP is blocked by firewalls and you are unable to connect.

9) When using UDP ensure the total bit rate (audio bit rate plus header bit rate) is no more than 80% of the ISP connection rate.  IP headers require around 20 kbps in addition to the audio bit rate. For example, with a 64 kbps connection the audio bit rate should be (64-20) x 0.8 = 31.2 kbps or lower. For TCP we suggest a limit of 50% or less.

10) Wireless IP connections can easily become congested and result in packet loss and audio drop-outs. It is very difficult to guarantee connection quality when there is no way of knowing how many people are sharing the same wireless connection.  Examples of wireless connections include:

1. WiFi connections within your LAN (These are unmanaged connections and should not be used to distribute audio when setting up IP connections);
2. GSM CSD and HSCSD connections; and
3. EV-DO, 3G UMTS or HSDPA phone connections.

Note: Be careful when using cell-phone connections at special events where thousands of people have mobile phones.  This can result in poor quality connections and audio drop-outs if cell-phone base stations are overloaded. The “Ss” wireless signal strength reading on the codec screen should be between 4 and 9 to connect reliably.

Complete the following check list and aim for a score of at least 8 out of 10 before going live.

[1] Cisco is a registered trademark of Cisco Systems, Inc. and/or its affiliates in the U.S. and certain other countries