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If you can't find what you are looking for in our FAQs, product tutorials and self-help guides please contact us via e-mail  if you are an existing customer open a support ticket. New customers can contact the sales team via


                                                                                   Fax and Faxmail

Q. Does C-Tel fax support colour?
A. No, currently we do not support colour. If you send a colour document via the C-Tel fax service it will appear in black and white.

Q. How does the C-Tel fax service work?
A. The C-Tel fax service uses the T.38 standard to send and receive real time fax over IP, enabling fax machines from different vendors to interoperate. In the T.38 architecture, fax signals are demodulated at the voice/ fax gateway and sent over the IP network as IP fax packets using either TCP or UDP, depending on the service environment. TCP provides 100% error-free transmission, but the downside is reduced real-time performance. Routers discard TCP packets first when congestion occurs. UDP has good real-time performance, since routers do not discard datagrams as readily as TCP packets. However, the downside of UDP is a reduced quality of service. It is possible for datagrams to get lost, arrive out of order, or to be duplicates. At the other end of the IP network, the remote gateway decodes IP fax packets and regenerates fax signals. Modulation methods that can be used with the T.38 format are V.21 Channel 2, V.27ter 2400, V.27ter 4800, V.29 7200, V.29 9600, V.17 7200, V.17 9600, V.17 12000, and V.17 14400.

Q. What is T.38?
A. The ITU recommendation, entitled 'T.38: Procedures for Real-Time Group 3 Facsimile Communication Over IP Networks', defines the procedures to be applied to allow Group 3 facsimile transmission between terminals, where a portion of the transmission path between terminals includes-besides the PSTN or ISDN-an IP network such as the Internet.

Q. What is the maximum speed for T.38 fax?
A. Currently, the maximum speed in which a Fax can be sent over T.38 is at 14.4kbps

Q. What about your Faxmail service?
A. C-Tel Faxmail also uses T.38. Faxes are delivered real time to your specified email inbox. When you send a fax it is delivered real time to the recipient. You receive email confirmation on whether your fax has been sent successfully or not.

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