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October 23, 2013 Real-time fax and other faxing methods - a Primer! Every fax has a real-time component. Every fax, whether sent via fax machine or email has a real-time component which implements the transmission of a document, over an established telephonic connection, from a sending device to a receiving device, page-by-page, with each page followed by receipt confirmation from the receiving device to the sending device, until all pages of the document are transmitted. Once all pages are sent, sender sends a final confirmation that the fax is completed. What is so important about real-time fax? Two components in the above definition are of particular significance in comparison to email or other types of communications. They are: a. Page-by-page confirmation means that sender does not proceed with sending further pages if something goes wrong therefore: If something goes wrong, sender knows exactly at which page the transmission stopped. Receiver cannot claim they did not receive a confirmed page. b. Real-time direct connection between sending device and receiving device means: There is no middle man that can alter the content of the fax in transit. Sender and receiver know and can agree on the delivery time. When the direct connection is secure, there can be no false confirmation that the fax was sent and no case for the receiver to deny it was correctly received at a given date and time. What is T.30 and T.38 fax? These are protocols that implement the real-time fax transmission. The T.30 protocol is used when the network connection carries analog signals as in PSTN or VoIP calls. The T.38 protocol is used when the network connection carries digital signals as in FoIP calls. T.38 encapsulates T.30, stripped of its analog considerations. Real-time fax and other faxing methods - a Primer! P. 1/5 What is hardcopy-fax? It is the classic method, where the sending and receiving devices are fax machines or MFDs (multi-function devices). Traditionally this method uses PSTN lines but with a line adapter that connects to a qualified T.38 service provider, faxes can go over the Internet from the fax machine or MFD. What are SMTP-fax and HTTPS-fax? These are different methods of faxing, having a storage component, but ultimately the sending and receiving device have to engage in a real-time fax call. SMTP (an email transport) is used to email a document to a fax server which then ‘faxes’ it to a recipient. In the reverse direction, an incoming fax is received by the fax server and emailed to the recipient as an email attachment. Referred to as ‘Electronic Fax’, this method is a very important component of contemporary faxing. SMTP faxing HTTPS (a web transport) is another way to submit a document to or from a sending or receiving device. It involves an HTTPS Client that transfers the document to and from an HTTPS Server that manages the actual faxing process. HTTPS faxing HTTPS Clients are proprietary and typically exist as add-ons to fax servers or in analog telephone adapters that connect the fax machine through the Internet. Real-time fax and other faxing methods - a Primer! P. 2/5 You will note from the previous diagrams that HTTPS and SMTP faxing require specialized fax servers at the Service Provider. These SMTP and HTTPS specialized servers incorporate a ‘Gateway’ component responsible for setting up the fax call via the Telephony Switch1 and faxing the document in real-time using T.30 or T.38. What is T.38 Real-time Fax? T.38 (FoIP) uses the Internet as a conduit; there is a direct connection between the sending and the receiving fax server or fax devices exactly as with the PSTN. The ‘fax server’ at the service provider is eliminated. Real-time faxing What were the motives behind SMTP and HTTPS faxing? To benefit from economy of scale, fax servers were developed to be able to process many fax calls at the same time. In addition to higher line densities, these servers offered more efficient ways to manage documents for faxing. The standard method for getting documents to and from the fax servers used SMTP to transport the document as an email attachment, giving users the ability to send and receive faxes as easily as they do email. This was an ideal solution until economy once again began to reshape the solution architecture, moving fax servers off corporate premise and into Service Provider facilities. Suddenly, the transport of documents using SMTP to and from the fax servers was no longer over the secure and reliable corporate LAN but over insecure and unpredictable Internet. Some turned to technologies like TLS, VPN and MPLS to solve the security and reliability issues. Others, possibly using a different economy/benefits trade-off model, arrived at an HTTPS based solution. 1Though these diagrams depict the specialised (SMTP or HTTPS) Server and Telephony Switch at the same Service Provider, they may in fact be hosted and managed by different Service Providers. Real-time fax and other faxing methods - a Primer! P. 3/5 Comparisons and Summary Hardcopy fax is here to stay as an acceptable and needed media as long as fax is required for signatures and positive confirmation of delivery. It is a ubiquitous fax capability needed for many, especially in the health, finance and legal domains. SMTP fax provides for email-to-fax and fax-to-email. Fax-to-email allows companies to manage fax in an electronic format for processing, filing, and archiving, while email-to-fax allows individuals to send documents directly from the PC or smartphone to a fax machine. HTTPS answered the need to send faxes securely from the fax server through the Internet, keeping gateways and other telephony components off the customer premise. It arrived at a time when customers were migrating telephony solutions from PSTN to IP and discovering that VoIP was not reliable for Internet fax, while T.38 solutions did not offer encryption and had inherited VoIP’s reputation for poor Internet fax delivery success rates. T.38, today, has evolved from its tenuous beginning into a highly reliable and robust solution for Internet fax. With T.38 surpassing the success rate of PSTN fax, encryption, and failsafe redundancy options, there is no argument for intermediary servers and specialized middleware as with HTTPS. In fact, HTTPS faxing raises the following issues Temporary storage at the provider level may or may not be HIPPA or SOX compliant Uses non-real-time (delayed) delivery notifications Requires delayed delivery confirmations to avoid false positives Use of additional specialised servers increases security and reliability risk Transport cost is inherently more expensive (more equipment more licences) Proprietary solution locked in to a vendor and out of new advancements in standards In view of these issues, and since there are no more arguments for HTTPS over T.38, T.38 should be seen as the de facto real-time fax solution of today. For any further questions, please contact: Daniel Dorsey Vice President – Channel Partnerships babyTEL Inc. (514) 448-0415 [email protected] www.babytel.net Real-time fax and other faxing methods - a Primer! P. 4/5 HTTPS AND T.38 MYTH BUSTERS Using HTTPS-fax is better than using T.38 directly in an unfounded claim. Before we delve into its arguments and rebut them, let’s recall that HTTPS is a way to get your document to and from the sending or receiving device. The actual faxing may involve T.38 and/or T.30, with no way to guarantee that only T.30 is used2. Let us now review the arguments used to back the claim and address them one by one. Argument #1: HTTPS-fax avoids poor network condition issues. False: Even if you can guarantee that the actual fax call only involves T.30, you would only avoid poor IP network conditions but still be susceptible to poor telephone network conditions. In fact, traffic analysis demonstrates conclusively that fax calls involving T.38 have a comparable success rate as those involving only T.30, with International T.38 calls often succeeding more than those using only T.30. Further, T.38 incorporates a number of technical solutions that deal effectively with burst-packet-loss and other poor IP network conditions. In addition, today, Internet Service Providers have watertight SLA’s promising ample bandwidth, low latency and little packet loss. Argument #2: Only HTTPS-fax adds security needed for compliance such as for HIPAA and SOX. False: T.38 can also be encrypted and without compliance concerns. Security and compliance, beyond encryption, involve how fax traffic is handled when it leaves and before it enters the corporate network. With an HTTPS-fax solution, the traffic must transit specialized fax servers’ storage buffers at the service provider and the solution may involve cloud components that have tenants, store user information or allow use of applications by users, much like SaaS solutions. Customers must therefore ensure the service provider handles the traffic in accordance with regulation and security requirements. Conversely, a direct encrypted T.38 connection with a telecom carrier acting as a conduit transporting information but not storing it has no elements that make the carrier subject to regulatory compliance. Argument #3: HTTPS-fax eliminates installation issues related to fax traffic passing the corporate firewall. False: Any security conscious business with proper firewall rules would only allow the necessary protocols for the specific devices that need them. This claim assumes the HTTPS protocol is always allowed for all devices on the network.

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