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2-10
2.2.2
Factors which will effect voice quality
Quality and reliability were the two darkest spots on VoIP's reputation for the past years. Here are the
main things that affect voice quality in VoIP and what can be done to maximize quality.
Bandwidth
Your Internet connection always tops the list of factors affecting voice quality in VoIP conversations. The
bandwidth you have for VoIP is the key for voice quality. For instance, if you have dial-up connection,
don’t expect great quality. A broadband connection will work right, as long as it is not spotty, and not
shared with too many other communication applications.
Equipment
The VoIP hardware equipment you use can greatly impact on your quality. Poor quality equipment are
normally the cheapest ones (but not always!). It is therefore always good to have as much information as
possible on an ATA, router or IP phone before investing on it and starting to use it.
NAT Mapping
If an IP extension registered to OM (OM puts behind router) via internet
or if multi-site networking is used
,
s
ome form of NAT (Network Address Translation) traversal is required. NAT is a function that allows
multiple devices to share the same public, routable, IP address to establish connections over the Internet.
NAT is present in many broadband access devices to translate public and private IP addresses.
Some ITSPs provide NAT traversal, but some do not. If your ITSP does not provide NAT traversal, you
have several options. Use NAT mapping with SIP-ALG (Application Layer Gateway) in the router.
It is necessary to configure remote-address information and configure port mapping on the Internet ingress
router or used the P2P traversal feature on OM. This enables devices on external networks to traverse
NAT (Network Address Translation) to get access to the OM.
Weather Conditions
The voice is terribly distorted by something called
static
, which is a small static electricity generated on
broadband lines due to thunderstorms, heavy rain, strong gusts, electrical impulses etc. This static is not
very much noticeable when you surf the net or download files, which is why we don’t complain about it
when we use the Internet for data despite it be here; but when you are listening to voice, it becomes
disturbing. It is easy to get rid of static: unplug your hardware (OM20/50, ATA, router or phone) and plug
it back again. The static will be brought to naught.
The effect of weather conditions on your connection is not something you can change. You can have some
short-term relief in some cases, but most of the time, it is up to your service provider to do something. At
