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Comparative Analysis of Techniques for Eliminating Spam in Fax over IP

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					                                                            (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                      Vol. 9, No. 1, 2011

  Comparative Analysis of Techniques for Eliminating
                Spam in Fax over IP

                       Manju Jose                                                           Dr. S.K. Srivatsa
                   Research Scholar,                                                        Senior Professor,
           Mother Teresa Women’s University                                         St.Joseph College of Engineering,
                   Kodaikanal, India                                                          Chennai,India.
                manjusaje@gmail.com                                                      profsks@rediffmail.com


Abstract— Fax over PSTN line suffered heavily in terms of high          this technology has improved over the years and now has
costs, call drops, improper imaging, corrupt messages etc. Fax          elaborate standards and mechanisms for faxing over IP.
over IP (FoIP) came as substitute to eliminate costly connection        Reducing cost is one of the most important reasons for
and transmission fees. With growing usage of FoIP, the spam is
also rising and ruining business prospects. The approaches from
                                                                        growing importance of fax over IP. Fax over IP can be almost
the point of view of regulations and technologies to curb spam          free in some cases. Also, fax over IP doesn’t demand
have been examined. Three technologies have also been                   expensive additional equipment because the existing fax
compared to suggest most suitable anti-spam technology.                 machine can be used for the purpose [16], [17].

                                                                                          II.       FAX OVER IP
   Keywords- Fax over IP (FoIP), S/Fax, SharePoint, Spam,               Consolidation of data and communication networks through IP
Filtering Spam Fax, Digital signature                                   is serving the objectives of reducing IT infrastructure costs
                                                                        while managing data and communication applications
                                                                        efficiently [19]. Communication technologies getting
                                                                        standardized through IP are causing an overlap between
                 I.       INTRODUCTION                                  network applications based on traditional communications
Facsimile or fax over the Public Switched Telephone Network             backbone and future IP environments. Organizations today are
(PSTN) line revolutionized the electronic transmission of               experiencing challenges in understanding their existing
documents and made Telex obsolete. A fax machine                        network applications. However, they can take advantages of
traditionally is an electronic device having scanner, modem             new IP-based approaches to data communications including
and a printer inbuilt. Fax machine transmits data in pulses             fax over IP (FoIP).
through a PSTN line to a recipient using a compatible fax               Most organizations are willing to implement VoIP to support
machine. The recipient fax machine transforms these pulses              their voice based operations. These organizations also need to
into images and prints the same on fax paper. The traditional           provide reliable faxing capabilities to their employees. It
method reserves its usage for PSTN line, and only one fax can           makes commercial sense as well to utilize the existing VoIP
be sent or received at a time.                                          technologies for supporting fax operations as well. There are
Fax over PSTN line suffered heavily in terms of high costs,             huge potential benefits for organizations consolidating fax
call drops, improper imaging, corrupt messages etc. There was           with voice systems through unified messaging applications.
a need to transform the way traditional fax systems worked.             Initially, fax systems have utilized reliable PSTN networks
Instead of using PSTN line, an idea of using IP was                     and have been backed by reliable T.30 fax protocol to
experimented with. This experiment was found to be                      establish and maintain communication between two fax
extremely successful as it cut down the costs and made faxing           devices. Now FoIP has new standards developed specifically
easier for users. Since fax over IP (FoIP) transmits data over          for FoIP making it possible for fax transmissions to utilize the
an already established network, it eliminates costly connection         Internet. Noticing this trend, fax manufacturers have started
and transmission fees.                                                  manufacturing fax equipments that can support transmission
Initially, fax over IP suffered from lack of quality as well as         over Internet as well [19].
efficiency and was not being considered as an ideal alternative
to traditional fax systems. These issues plagued fax over IP                              III.      TECHNOLOGIES
system as it didn’t have a technology of its own. Initially, it         FoIP is supported by two technologies such as “store-and-
used Voice over IP (VoIP) as its base technology. However,              forward” (T.37) and “realtime” (T.38). These technologies



                                                                   48                              http://sites.google.com/site/ijcsis/
                                                                                                   ISSN 1947-5500
                                                            (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                      Vol. 9, No. 1, 2011

utilize the standard T.30 fax definition to recognize data being            5. Least Cost Routing
transferred and to ensure compatibility with existing fax                   6. Better utilization of new IP equipment
devices. These technologies differ from each other in methods               7. Eliminate the fax boards
of delivery and confirmation receipts. Real-time FoIP, based
on the International Telecommunications Union (ITU)                     VoIP networks are increasingly entering private and public
standard T.38, elaborates the necessary technical features for          organizations with IP Telephony technology. These
transferring fax in real-time mode between two standard                 organizations would naturally want to leverage the value and
Group 3 facsimile terminals over Internet or other IP based             convenience of single IP communications network. Standard
networks. T.38 is generally preferred as FoIP protocol because          VoIP Codecs have been designed for voice conversations.
of its ability to align with the technologies of faxes over             These Codecs allow certain amount of latency and packet loss,
PSTN.                                                                   which can still be accepted in a voice conversation.
T.30 handles IP fax transmission through like a standard fax            However, faxes cannot afford to accept even small amounts of
call facilitating an end-to-end communication. With T.38,               latency or any packet loss, rendering standard VoIP Codecs
sending and receiving fax is similar to fax handling of non-            unacceptable for reliable faxing.
FoIP fax devices. This involves establishing a session, sending         This limitation forces organizations to retain analog lines on
and verifying the transmission of one or more pages and                 PBX, or deploy expensive fax boards to manage their fax
finally completing the session with positive confirmations              traffic. These extra expenses affect the ROI negatively that
from both sides. FoIP-enabled transmission is different as the          organizations expect from their VoIP network investment.
server traverses first part of the communication to the network         This scenario also requires organizations to maintain legacy
on IP technology rather than the PSTN. The session can use              communication equipments with their modern IP network
T.38 for transmission if the partner device is directly                 infrastructure.
addressable on the same network. The IP switch converts T.38            FoIP can utilize TCP/IP standards and technologies to connect
packets to standard T.30 packets over PSTN if the devices are           to the closest PSTN access to send and receive faxes. FoIP, as
separated by the telephone line.                                        a public standard, is supported by most of the vendors’ VoIP
IP fax mechanism has two approaches namely boardless                    gateways. Rather than connecting a fax card to the PSTN,
approach and the boarded approach for an Ethernet                       FoIP device can connect directly to the T.38 supported VoIP
connection. Boardless system makes the fax works through                gateway. This principle is applicable on both inbound and
DSPs (digital signal processors) located in IP routers. DSP             outbound faxes [20]. eFax uses the store-and-forward
manages transmission and conversion of T.38 packets to T.30             capabilities as per T.37 standard to enable sending of faxes as
packets. Since there is greater awareness among organizations           emails. This obviously doesn’t happen in real-time, which is
over implementation of VoIP, there are lesser chances that              the expected legal standing associated with fax. The fax is
organizations will go for FoIP before VoIP.                             forwarded as email to an email server and then transmitted as
Rather organizations are likely to utilize the already existing         an email attachment to a fax device for physical faxing.
VoIP infrastructure to minimize the expense of adding FoIP to           This method cuts IT support requirements for fax, but
the same infrastructure. Also, VoIP will offer the required             introduces limitations such as higher costs. Other providers
support already included in its routing infrastructure.                 use their VoIP networks to transmit fax, but this method
Organizations need to ensure that investments in VoIP                   requires an Analog Terminal Adaptor (ATA) hardware device
infrastructure are justified in including support for FoIP as           into which a traditional fax machine must be plugged. These
well.                                                                   services are not enabling the users to fax straight to a receiver
Organizations adopting an IP environment need to enhance the            desktop.
benefits of their existing fax technologies by enabling them to         These limitations force organizations to not to use their
support FoIP communications.                                            existing VoIP networks for faxing. These organizations have
A research [19] surveyed more than 500 fax users and                    limitations in realizing that VoIP capabilities added to their
potential users on their FoIP needs and expectations. This              infrastructure also have added FoIP capabilities, without
research identified the following most sought after benefits            additional effort or expense [21].
while implementing FoIP technologies:                                   There has been growing consensus regarding using existing
                                                                        VoIP networks to support faxing to save efforts and cost. Still,
    1. Savings in Total Cost of Ownership (TCO) due to                  notable differences between VoIP and FoIP need to be
       network consolidation                                            understood by the organizations before taking a decision.
    2. Ability to push consistent fax solution throughout the           For organizations that have already implemented VoIP
       entire network including remote locations.                       technologies, adding FoIP capabilities on the top of VoIP
    3. Improved IT management                                           infrastructure would make perfect business sense.
    4. Device/application integration                                   However, for organizations that are yet to decide on type of IP




                                                                   49                              http://sites.google.com/site/ijcsis/
                                                                                                   ISSN 1947-5500
                                                            (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                      Vol. 9, No. 1, 2011
capabilities, they would scale up to, a thorough comparison             big relief to business users with numerous advantages
between VoIP and FoIP is definitely required.                           associated with it such as compatibility, retention and

FoIP is less tolerant to delays in comparison to VoIP. As delay         integrity. This article also highlighted the challenges of spam
in the absence of keep-alive mechanisms may force a session             or junk fax that were ruining the business prospects of fax
to drop. However, VoIP would absorb such network                        over IP systems.
impairments and would force delayed browsing experience to              The perspectives of spam fax differ for the recipients and
the users. FoIP is also less tolerant towards packet errors or          organizations dealing in fax marketing [14]. The costs
losses in comparison to VoIP. For communication reliability,            attached with spam are high and fax spammers are not
FoIP may require an error-correcting but delay-adding                   authorized to use fax paper and toner of unwilling recipients to
protocol such as TCP to ensure delivery confirmation or repeat          send sales pitches. Further, fax spammers shouldn’t be
requests [22]. Considering the tighter integration of FoIP with         allowed to tie up bandwidth, computing power, and storage of
real-time transmission and reliability, FoIP is treated as first        unintended recipients as they haven’t paid for it [18]. With
possible alternative by the organizations.                              aggressive marketing pitches over fax machines, email boxes
                                                                        and cell phones, the list of offenses that deserve the spam
          IV.      THE GROWTH STORY SO FAR                              handle is also growing [10].
A research report [2] highlighted that fax revenues would
continue to grow from $270 million in 2005 to $400 million in                          VI.        THE FIGHT BACK
2010, achieving a remarkable compound annual growth rate                A new lobby of anti spam activists has decided take on fax
(CAGR) of 8.2%. This report estimated that fax over IP sales            spammers and these activists have been fighting against
would grow by a 50.7% CAGR to $245 million in 2010 and                  unsolicited fax messages through claims of damages and
non fax over IP fax sales would decrease to $155 million in             advocating for a law on spam faxes.
2010. This report further added that fax over IP systems would          A suit [9] filed to get junk or spam faxes banned was different
dominate the market by 2010 with integration of VoIP.                   in approach as it didn’t claim damages. Rather, it helped in
Another research report [4] highlighted that more than 100              establishing a junk fax ruling under which sending of junk
billion fax pages are transmitted around the globe on a yearly          faxes was considered a criminal act.
basis despite efforts to become a paperless society. This               A prominent case [13] used junk fax law to sue violator over
research report also highlighted that fax over IP markets               email spam and sought damages proving the ground
would continue to grow rapidly during the five-year forecast            comprehensively. This case argued that computer was also
period unfazed by economic recession. This report further               acting as fax machine and that email was really no different
highlighted that fax has certain advantages over e-mail as it           from fax over IP. This case further argued that received spam
largely remains compatible across various devices and                   email using a phone line connection and printed message
systems, retains the format of complex documents and finally            demonstrate suitability of trial of this case under junk fax law.
sends documents in non-editable format so that the recipients           An article [8] cited doubts in the opinions regarding
do not modify them.                                                     willingness of courts to apply junk fax law, as most of the
A research report [3] on fax messaging markets observed that            existing state laws on spam are weak and counterproductive.
patent law situation with respect to fax over IP has undergone
radical changes. This report further added that fax over IP                    VII.          SPAM FAX: CURBING THE MENACE
would continue to enjoy growth rates that were earlier                  An article [14] suggested certain measures to prevent spam in
diminished due to economic downturn. This report concluded              fax over IP as per the provisions of the Junk Fax Prevention
with fax over IP market projections of $ 1.575 billion in 2013.         Act [15]. The recipient can contact the sender directly and
A research report [5] on computer based fax markets for the             express his/her unwillingness to receive spam fax messages.
period of 2009-2014 and observed that usage of IP has                   The recipient can also choose “opt out” option to block his/her
contributed towards tremendous growth of fax over IP. This              fax number from fax mailing lists. The recipient also has a
report highlighted phenomenon of multi function peripherals             choice to approach a regulator and file a complaint or even
(MFPs) and integration of business computing systems. The               claim damages.
MFPs would account for 32% of revenues produced through                 A suggestion was made regarding integrating FoIP with
fax over IP industry. This integration has also fuelled demand          Microsoft SharePoint to eliminate spam and security risks.
for fax over IP services. This report forecasted that desktop           This integration can ensure the right movement of documents
faxing would account for 70% share of fax systems, out of               and junk or spam is filtered out [1]. This article further
which 42.5% share would be attributed to unified messaging.             elaborated that FoIP, when integrated with SharePoint,
                                                                        provides efficient inbound routing of fax into SharePoint sites.
     V.         SPAM IN FAX: THE INSIDER’S PERSPECTIVE                  This feature enables the users to search content, metadata tags,
An article [1] argued that fax over IP systems have brought             and optical character recognition (OCR) features of fax




                                                                   50                              http://sites.google.com/site/ijcsis/
                                                                                                   ISSN 1947-5500
                                                              (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                        Vol. 9, No. 1, 2011
documents to differentiate spam from necessary documents                           TABLE I.             Comparative Analysis
and apply rule based routing. The users also have the                        Technologies       Integration     S/FAX over       Spam Fax Filter
                                                                                               of FoIP with        IP (PDF       (Non- rasterized
provision of triggering an automated SharePoint work flow
                                                                                                SharePoint         Format)             Format)
process to ensure that fax documents go to the right folders or              Mechanism         Inbound rule     Use of S/FAX        Conversion of
destinations while filtering junk out of the system.                                           base routing       over IP to       rasterized form
Another article [7] criticized the spam filters for their                                        of fax into       generate      of fax image into
                                                                                                 SharePoint      secure mails       non-rasterized
application in content sorting only. Moreover, most of the                                           sites           in pdf              form
spam filters sort the spam after accepting the messages. High                 Filtering /        Searching        Verifying        Verifying non-
volume of spam forbids the users from receiving it and all                   Segregation           content,     integrity and     rasterized forms
messages classified as spam are automatically deleted. This                                   metadata tags          digital      of the fax image
                                                                                                  and OCR        signature of    against spam fax
causes difficulties to genuine senders as their messages are                                  features of fax          pdf       characteristics to
deleted without any reason being assigned. Using spam filter                                   documents to     documents to      filter spam from
on protocol level would reject the spam and assign reason for                                    filter spam       allow fax        necessary fax
doing so. Such spam filters are rare. This article advocated the                                     from        messages to         documents.
                                                                                               necessary fax          enter
use of pdf format over spam filters to counter spam faxes. A                                     documents
suggestion was made regarding using secure fax (S/FAX) over                Load on Network           High          Low                 High
IP to generate secure mails in pdf format containing sender’s                 Disposal            After fax      Before fax       After fax enters
name, address, and digital signature. This pdf can also be                                        enters the     enters the         the system
                                                                                                    system        system
given password protection, if required. Upon receipt, the pdf               Response Time            High          Low                 High
reader can verify the integrity of the document as well as the
digital signature and allow the receiver to either view it or
discard as spam.                                                                             IX.           CONCLUSION
An article [11] suggested charging fax spammer from $500 to
$1500 for every unsolicited fax they send. The article added              S/FAX over IP approach proposed by Engelbert is
that this amount could become significant if fax spammers                 conclusively better than rest of the approaches, as this
send many faxes. The recipient needs to keep track of all                 approach does not allow the spam fax to get into system.
unsolicited faxes with date & time stamps to be used for                  Rather, this approach proposes to use spam filter to accept or
claims.                                                                   discard fax messages subject to verification of integrity and
A technology [6] has also been proposed regarding spam fax                digital signature of incoming fax messages. Also, this
filter that can transform a rasterized form of a fax image into           approach proposes to assign reasons for rejection of fax
non-rasterized forms. Non-rasterized forms of the fax image               messages enabling the senders to receive the status of their
can then be checked against spam fax characteristics, or                  messages.
characteristics of fax images not known as spam. The fax
image is declared as spam if it tests favorably to at least one of                           X.          LIMITATIONS
the known characteristics of spam fax. In case, the fax image             The researcher experienced certain limitations while
doesn’t conform to any of the characteristics of spam fax, it             conducting this research as there is no benchmark available,
can be declared as non spam.                                              which could be taken into consideration for comparing the
Another article [12] suggested complaining to regulator and               technical approaches to prevent spam in fax over IP. The
highlighting the matter to draw mass attention to curb the fax            researcher interacted with fax users to understand their
spam menace.                                                              expectations from these spam prevention approaches to
                                                                          identify the key indicators for comparison. The researcher
            VIII.       COMPARATIVE ANALYSIS                              attached high significance to pre disposal of spam faxes as this
A comparative analysis as given in table.I involving three                would prevent the spam faxes from entering into the system.
approaches [1], [6], [7] has been done to understand the                  The significant factors may be different for different users.
unique characteristics associated with each approach.
While comparing, the key indicators such as disposal of spam                           XI.         FUTURE RESEARCH WORK

faxes, system overload, response time etc were kept in                    The researcher is willing to work and explore this area more in
consideration. The researcher had attached higher significance            order to identify best technologies and approaches to prevent
to anti fax spam technology offering pre disposal of spam                 spam in fax over IP. The researcher also intends to bring more
faxes as this would largely save the network from getting                 technologies and approaches under the ambit of comparisons.
flooded with spam faxes resulting in higher load on resources.            A detailed research can be initiated on the basis of already
                                                                          covered issues and suitable statistical parameters can be used
                                                                          for rigorous technical comparisons. Developing a globally
                                                                          acceptable technology or approach to prevent spam in fax over




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                                                                                                        ISSN 1947-5500
                                                                         (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                                   Vol. 9, No. 1, 2011
IP is also a possibility in future.                                                   [12]   Nefer, B. (2010), How Do I Cancel Spam Faxes?
                                                                                             http://www.ehow.com/how_6885111_do-cancel-spam-faxes_.html.
                                                                                      [13]   Seymour, J. (2003), Michigan Man Uses Junk FAX Law to Sue Sears
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[1]    Campbell, S. (2010), The Many Benefits of FoIP and Microsoft                   [14]   Stevens, P. (2006), Spam Fax Facts, http://faxing-service-
       PowerPoint,         http://www.tmcnet.com/channels/foip/articles/77591-               review.toptenreviews.com/spam-fax-facts.html.
       many-benefits-foip-microsoft-sharepoint.htm.                                   [15]   The       Telephone     Consumer        Protection    Act    (2005),
[2]    Davidson Consulting (2006), Computer-Based Fax Markets, 2005–                         http://www.junkfaxes.org/federal_law.htm.
       2010, December 2006                                                            [16]   Unuth, N. (2010), IP Faxing: A Cheaper Way of Sending Fax,
[3]    Davidson Consulting (2009), Fax Messaging Markets, 2008-2013, July                    http://voip.about.com/od/faxingoverip/a/IPFaxingIntro.htm.
       2009                                                                           [17]   Unuth, N. (2010), Reasons for Using Faxing over IP,
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       2009                                                                           [18]   Warner, J. (2003), How much does spam really cost? The Miami
[5]    Davidson Consulting (2010), Computer-Based Fax Markets, 2009-                         Herald, March 10, 2003.
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[8]    Festa, P. (2002), Newsmaker: A cybersage speaks his mind, CNET                        April 2006.
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[10]   Hansen, E. and Olsen, S. (2002), Spam: It's more than bulk e-mail,
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[11]   Miller,     N.      (2010),    Stop    Fax    Spam       For      Good,
       http://ezinearticles.com/?Stop-Fax-Spam-For-Good&id=3577712.




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