Are there any bandwidth concerns (or QoS concerns) when overlapping Fax over IP onto a VoIP network?
As with any IP-based service, the network should be provisioned to provide the necessary bandwidth (which will vary depending on usage patterns.) However, Fax over IP traffic typically uses only about 1/3 the bandwidth of VoIP traffic, and therefore will have a much smaller impact on the required network bandwidth needs. a) The SR140 and TR1034 use T.38 over UDP to send fax. Other products on the market use a codec (G.711 for example) to send fax. These are two very different ways to transport fax over IP. G.711 over RTP is a VoIP connection – think of it as streaming a fax over a VoIP line. VoIP is consuming 64kbps. However, T.38 is a protocol designated for FoIP and does not use that much bandwidth. b) The SR140 and TR1034 will put traffic on the IP line at the modulation rate negotiated to the end fax device off the PSTN. So, for example, if you have a clean V.17 connection, you are consuming bandwidth on the IP line at a rate of 14.4 kbps. HOWEVER – it’s not this straight forward (
