Tieline Bridge-IT, User Manual

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212 Bridge-IT Manual v4.0
© Tieline Research Pty. Ltd. 2019
Port Forwarding: Tieline TCP and UDP Port Settings
For your Tieline Codec to communicate over the public internet an IP Address alone is not
sufficient. In TCP/IP and UDP networks the codec port is the endpoint of your connection. Ports
are doorways for IP devices to communicate with each other. Picture a house and imagine the
front door is the entry point represented by a public or private IP address. Then you want to get to
several codecs in different rooms of the same house and ports represent the doors to each of
those rooms. In principle this is how port addressing works.
For example, several codecs may dial into your studio using the same public static IP address. In
this situation it is necessary to configure codec 'programs' with audio streams using different audio
ports for discretely routing each incoming and outgoing audio stream. By doing this your studio's
network routers know where IP packets for each audio stream should be routed, i.e. to which
codec and respective audio outputs.
When data packets are received from remote codecs at a particular public IP address, port
information is translated from data packets to ensure the correct packets are sent to the correct
studio codecs. This process is performed by PAT (Port Address Translation), which is a feature of
NAT (Network Address Translation) devices.
Tieline codecs use TCP ports for setting up the communication session and UDP ports for
streaming audio. While TCP ports are generally open, UDP ports are generally blocked by network
devices which contain firewalls and will stop you delivering your audio. Depending on the codecs
you are using, you need to configure your firewall to allow TCP and UDP protocols to pass through
the ports listed in the table below.
18.3 Tips for Creating Reliable IP Connections
The following 10 tips are provided to help obtain the best possible IP connection between two
codecs, without paying for Quality of Service (QoS).
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 ISP. 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® switching and routing equipment.):