{"id":1485,"date":"2012-04-11T20:07:33","date_gmt":"2012-04-11T20:07:33","guid":{"rendered":"http:\/\/192.168.16.235\/?page_id=1485"},"modified":"2020-01-24T15:56:21","modified_gmt":"2020-01-24T15:56:21","slug":"smart-foip","status":"publish","type":"page","link":"https:\/\/commetrex.com\/?page_id=1485","title":{"rendered":"Smart FoIP"},"content":{"rendered":"<p>[vc_row css_animation=&#8221;&#8221; row_type=&#8221;row&#8221; use_row_as_full_screen_section=&#8221;no&#8221; type=&#8221;grid&#8221; angled_section=&#8221;no&#8221; text_align=&#8221;left&#8221; background_image_as_pattern=&#8221;without_pattern&#8221; css=&#8221;.vc_custom_1578665619532{padding-top: 60px !important;}&#8221; z_index=&#8221;&#8221;][vc_column width=&#8221;1\/2&#8243;][vc_column_text]Smart FoIP, Commetrex\u2019 patented technology, has been integrated into BladeWare, and is optionally available with <span style=\"text-decoration: underline;\"><strong><a title=\"T.38 Fax Relay\" href=\"http:\/\/commetrex.com\/customers\/customers-by-name\/t-38-fax-relay\/\">T.38 Fax Relay<\/a><\/strong><\/span> and <span style=\"text-decoration: underline;\"><strong><a title=\"Multi-Modal Terminating Fax (MMTF)\" href=\"http:\/\/commetrex.com\/products\/multi-modal-terminating-fax-mmtf\/\">Multi-Modal Terminating Fax (MMTF)<\/a><\/strong><\/span> for use in SIP networks. Smart FoIP eliminates the problems caused by late-arriving T.38 re-Invites from the receiving gateway, which can cause the call to fail if the re-Invite is accepted when it should actually be rejected.<\/p>\n<p>Commetrex has found that significant practical problems with SIP negotiations for FoIP calls exist in carrier-based networks. After much testing and analysis, we have developed \u201cSmart FoIP\u201d, which improves the reliability of fax-session establishment for media servers, ATAs, and access gateways. The technology increases the likelihood of a session remaining in G.711 fax pass-through mode, so it also includes a major technology advance that eliminates PCM-clock synchronization problems, which are responsible for a large percentage of G.711 pass-through fax failures.<\/p>\n<p>[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/2&#8243;][vc_column_text]<iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/fj1iQkIpTBA?rel=0\" width=\"100%\" height=\"315\" frameborder=\"0\"><\/iframe><br \/>\n<em>Above: Watch this video to learn more about Smart FoIP. Angie, a systems integrator, explains the benefits of Smart FoIP to her client, John, and how it can help his business.<span style=\"text-decoration: underline;\"><strong> <a title=\"Videos\" href=\"http:\/\/commetrex.com\/company\/videos\/\">&#8230;more videos<\/a><\/strong><\/span><\/em>[\/vc_column_text][\/vc_column][\/vc_row][vc_row css_animation=&#8221;&#8221; row_type=&#8221;row&#8221; use_row_as_full_screen_section=&#8221;no&#8221; type=&#8221;grid&#8221; angled_section=&#8221;no&#8221; text_align=&#8221;left&#8221; background_image_as_pattern=&#8221;without_pattern&#8221; css=&#8221;.vc_custom_1578316708859{margin-top: 80px !important;padding-bottom: 70px !important;}&#8221; z_index=&#8221;&#8221;][vc_column][vc_row_inner row_type=&#8221;row&#8221; type=&#8221;grid&#8221; text_align=&#8221;left&#8221; css_animation=&#8221;&#8221; el_class=&#8221;bd-first-sec&#8221;][vc_column_inner width=&#8221;5\/6&#8243;][vc_column_text]Commetrex developed its T.30 in 1994, its T.38 relay in 1998, and invented terminating T.38 in 2001. This unsurpassed experience led us to discover that as much as 20% of FoIP transaction failures aren\u2019t caused by T.38 or other interop problems, but by the session negotiations that occur at the beginning of a SIP-based FoIP call.<\/p>\n<p>Another major benefit of Smart FoIP for the gateway developer is its encapsulation of the logic needed to implement SIP support for T.38 version 3 with V.34 support.<\/p>\n<p><em>Read about<span style=\"text-decoration: underline;\"><strong> <a title=\"Smart ATA\" href=\"https:\/\/netgencommunications.com\/product_detail\/smart-ata\/\" target=\"_blank\" rel=\"noopener noreferrer\">Smart ATA<\/a><\/strong><\/span>, featuring Smart FoIP, from <span style=\"text-decoration: underline;\"><strong><a title=\"NetGen Communications\" href=\"http:\/\/www.netgencommunications.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">NetGen Communications<\/a><\/strong><\/span>.<\/em>[\/vc_column_text][\/vc_column_inner][vc_column_inner width=&#8221;1\/6&#8243;][vc_single_image image=&#8221;5281&#8243; img_size=&#8221;full&#8221; qode_css_animation=&#8221;&#8221;][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row][vc_row css_animation=&#8221;&#8221; row_type=&#8221;row&#8221; use_row_as_full_screen_section=&#8221;no&#8221; type=&#8221;grid&#8221; angled_section=&#8221;no&#8221; text_align=&#8221;left&#8221; background_image_as_pattern=&#8221;without_pattern&#8221; z_index=&#8221;&#8221; css=&#8221;.vc_custom_1578318800266{padding-top: 60px !important;padding-bottom: 60px !important;background-color: #f0f0f0 !important;}&#8221;][vc_column width=&#8221;1\/2&#8243; el_class=&#8221;white-box&#8221;][vc_column_text]<\/p>\n<h2>Features<\/h2>\n<ul>\n<li>Puts intelligence into acceptance of SIP re-Invites to T.38<\/li>\n<li>Improved Call-completion rates<\/li>\n<li>Included in <em>BladeWare<\/em><\/li>\n<li>Optional for Multi-Modal Terminating Fax (MMTF)<\/li>\n<li>An option for T.38 Fax Relay<\/li>\n<li>Integrates with OEM\u2019s call-control subsystem<\/li>\n<li>Utilizes Commetrex\u2019 fax modems and call classifier<\/li>\n<li>Encapsulates call set-up for V.34<\/li>\n<\/ul>\n<p>[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/2&#8243; el_class=&#8221;white-box&#8221;][vc_column_text]<\/p>\n<h2>Benefits<\/h2>\n<ul>\n<li>Improved subscriber satisfaction<\/li>\n<li>Reduced support costs<\/li>\n<li>Reduced network costs<\/li>\n<li>Reduced call times<\/li>\n<li>Reduced development costs<\/li>\n<\/ul>\n<p>[\/vc_column_text][\/vc_column][\/vc_row][vc_row css_animation=&#8221;&#8221; row_type=&#8221;row&#8221; use_row_as_full_screen_section=&#8221;no&#8221; type=&#8221;grid&#8221; angled_section=&#8221;no&#8221; text_align=&#8221;left&#8221; background_image_as_pattern=&#8221;without_pattern&#8221; css=&#8221;.vc_custom_1578667657644{padding-top: 60px !important;padding-bottom: 60px !important;}&#8221; z_index=&#8221;&#8221;][vc_column][vc_column_text]<\/p>\n<h2>Background<\/h2>\n<p>Not all T.38 implementations exhibit the same performance in the field, even if they conform to the T.38 recommendation. You could easily have a widely interoperable T.38 and have an intolerably low transaction success rate. It is difficult to verify interoperability, and it\u2019s even more difficult to determine performance. And to make matters worse, the parameters of T.38 performance aren\u2019t even widely known.<\/p>\n<p>Beyond interoperability, much of what we call T.38 performance is inherent in its implementation, not the specification. It\u2019s safe to say that the best T.38 designs were developed by an engineer that has successfully fielded T.30, the protocol of terminating fax. This is because T.38 does not give any guidance on how to improve delay tolerance, for example, but, as we know, it is improved through so-called spoofing techniques implemented by skilled T.38 relay developers that thoroughly understand T.30. Better relays can handle up to five seconds of round-trip delay in the IP path.<\/p>\n<h2>The Problem<\/h2>\n<p>Through rigorous testing, Commetrex has learned the effect on call set-up performance of how an ATA, a gateway, or a fax server handles late-arriving T.38 re-invites. Signaling delays within a carrier network can cause a gateway without Smart FoIP to effectively kill a fax session by blindly accepting a T.38 re-invite from its off-ramp peer in a non-V.34 session.<\/p>\n<h2>The Solution<\/h2>\n<p>To solve this problem, we developed Smart FoIP, Commetrex\u2019 licensed software that includes patent-applied-for technology that puts intelligence into whether to accept a T.38 re-invite, eliminating this as a cause of failed sessions, boosting transaction success rates, often by 10%.<\/p>\n<p>On one large-footprint IP network we tested, fully 10-percent of the T.38 re-invites took over five seconds to arrive, with most of those resulting in transaction failures. These calls averaged over 8 seconds from the initial Invite\u2019s 200OK to the subsequent re-Invite. Applying our new technology took care of the problem, boosting an IP-based fax-broadcast server\u2019s transaction success rate to equal that of a multi-line intelligent ISDN fax board.<\/p>\n<p>An ATA or gateway with Commetrex\u2019 proprietary relay technology attaches a V.21 modem (along with other analysis algorithms) to the media streams at the beginning of the call. The on-ramp gateway analyzes the decoded V.21 data to track the T.30 states of the calling and called terminals. The called terminal will repeatedly send its initial message (DIS) until the calling terminal sends its response. Once the calling fax terminal receives a complete DIS, it sends its response (DCS) within 75 milliseconds. Therefore, once this calling-terminal response (DCS) is received by the called terminal, uninterruptable modem operations have begun, and the gateways can no longer switch the session to T.38 without possible corruption of the T.30 states being maintained in the endpoint terminals.<\/p>\n<p>With Smart FoIP, once the on-ramp gateway detects the preamble to the calling fax terminal\u2019s response, it will no longer accept the T.38 re-invite, continuing the transaction in G.711 mode and avoiding the session failures caused by the transition occurring during a modem session.<\/p>\n<p>In the case of an IP-based fax server there are no modems since the server is connected directly to the IP network, and the T.30 state machine and the T.38 protocol engine are both on the same system. Therefore, there is no need for a V.21 modem since the server maintains its own T.30 calling-terminal state. The server will accept T.38 re-invites up to the point where it has received the called terminal\u2019s DIS, refusing all subsequent re-invites.<\/p>\n<h2>G.711 Pass-Through Fax<\/h2>\n<p>Of course, refusing a T.38 re-invite means continuing the session in what is called \u201cG.711 pass-through mode\u201d, making support for G.711 pass-through in server applications a Smart FoIP prerequisite. As Commetrex\u2019 <em>BladeWare<\/em> MMTF, and T.38 Fax Relay all support both T.38 and G.711 pass through, Commetrex\u2019 TerminatingT38 does not. Smart FoIP is now included in <em>BladeWare<\/em> beginning with Release 2.4. Of course, gateways and ATAs support both, and they are plagued by this problem unless they have Commetrex technology with Smart FoIP inside.<\/p>\n<p>But, you may have wondered, doesn\u2019t Smart FoIP mean more G.711 pass-through faxes? And don\u2019t they inevitably fail? That\u2019s a good question because the answer is yes, G.711 fax sessions do often fail unless the session includes a fax relay with Smart FoIP\u2019s proprietary buffer-management technology.<\/p>\n<p>Carriers have done a great job of virtually eliminating dropped packets, but PCM clock-synchronization problems remain. The problem results from jitter buffer under-run and over-run caused by the PCM clocks at opposite ends of the link (the endpoint terminals) not being equal, which is always the case. The question, of course, is how unequal are they and how long is the fax? The more unequal they are, the quicker the session fails. Long-enough G.711 pass-through faxes and even long T.38 sessions can fail if the jitter buffers are not effectively handled. Commetrex\u2019 Smart FoIP relay technology and <em>BladeWare<\/em> media servers include buffer-management technology that eliminates PCM-clock-synchronization problems in G.711 pass-through and T.38 fax sessions.<\/p>\n<p>In <em>BladeWare<\/em>, our HMP fax-server platform, terminating G.711 IP faxes use the incoming G.711 packet stream for timing purposes. For every 20ms of G.711 data it receives, for example, the system generates an equal amount of data for transmit, removing clock-synchronization errors. So, <em>BladeWare\u2019s<\/em> G.711 data are exactly in sync with the remote relay&#8217;s sample clock, and we never overflow or underflow our G.711 buffers, nor does the remote gateway since we are slaved to its clock.<\/p>\n<p>However, in relay-to-relay T.38 operations, there are two analog PCM sample clocks: one at the remote transmitting fax and the other at the local re-modulating modem. These two clocks always have a different rate. Bits generated at the transmitting endpoint fax terminal must be retransmitted by the off-ramp gateway\u2019s local modem. If the remote fax is generating bits faster than the off-ramp gateway\u2019s local modem can send them out to the fax terminal, off-ramp overflow eventually occurs. In the reverse case (off-ramp faster than transmitting fax terminal), the on-ramp modem will run dry since the off-ramp gateway is sending the bits out faster than it receives them, and T.38 relay will have to spoof some bits to keep the transmitter running (provided you have a well designed relay, of course). Underflow is not as much of a problem, since the relay can insert additional flags in V.21 data or padding bits at the end of a line of image data (Does your relay do that?). But overflow is a problem as valid data must be tossed (and modems just hate that).<\/p>\n<p>Enter Commetrex innovation. Smart FoIP includes patent-applied-for fax-aware jitter-buffer management that is specific to G.711 pass-through fax and eliminates PCM-clock sync problems in gateways.<\/p>\n<h2>Product Configurations<\/h2>\n<p>Smart FoIP is an inherent feature in <em>BladeWare<\/em>. Support for both T.38 and G.711 is required for Smart FoIP to work in <em>BladeWare<\/em>. Smart FoIP is optional in Multi-Modal Terminating Fax (MMTF) and T.38 Fax Relay licensed media technologies.<\/p>\n<p>Smart FoIP is a module that receives events from the modem package and sends events to the OEM\u2019s call-control and buffer-management software. Without Smart FoIP, none of the licensed technologies listed above have any interface with the licensee\u2019s call-control system. But Smart FoIP, since it detects modem events and sends messages to call control, effectively creates an intelligent bridge between the two. This package is fully documented in a developer\u2019s manual.<\/p>\n<h2>FoIP Interoperability<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-968\" title=\"T.38 Interop Lab\" src=\"http:\/\/commetrex.com\/wp-content\/uploads\/2011\/12\/T38_Seal_150_best-125x125.jpg\" alt=\"T.38 Interop Lab\" width=\"100\" height=\"100\" \/>Commetrex has led the industry effort for T.38 interoperability since January 2002, when it launched the <strong><a title=\"T.38 Interop Lab Test Results\" href=\"http:\/\/commetrex.com\/products\/t-38-interop-lab-test-results\/\" target=\"_blank\" rel=\"noopener noreferrer\">T.38 Interoperability Test Lab<\/a><\/strong>. Recently, Commetrex has done extensive interoperability testing with the <em>BladeWare<\/em> HMP telephony platform, with international carriers, service providers, and enterprises.<\/p>\n<h2>Ordering Information<\/h2>\n<ul>\n<li>Smart FoIP for MMTF: PN 60324<\/li>\n<li>Smart FoIP for PowerRelay for T.38: PN 60325<\/li>\n<\/ul>\n<h2>Related Publications<\/h2>\n<ul>\n<li><a title=\"T.38 Fax Relay Software\" href=\"http:\/\/commetrex.com\/products\/t-38-fax-relay-software\/\">T.38 Fax Relay Product Bulletin<\/a><\/li>\n<li><a title=\"Multi-Modal Terminating Fax (MMTF)\" href=\"http:\/\/commetrex.com\/products\/multi-modal-terminating-fax-mmtf\/\">Multi-Modal Terminating Fax Product Bulletin<\/a><\/li>\n<li><a title=\"BladeWare HMP Media Server\" href=\"http:\/\/commetrex.com\/products\/bladeware-hmp-media-server\/\"><em>BladeWare<\/em> Product Bulletin<\/a><\/li>\n<\/ul>\n<p>[\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>[vc_row css_animation=&#8221;&#8221; row_type=&#8221;row&#8221; use_row_as_full_screen_section=&#8221;no&#8221; type=&#8221;grid&#8221; angled_section=&#8221;no&#8221; text_align=&#8221;left&#8221; background_image_as_pattern=&#8221;without_pattern&#8221; css=&#8221;.vc_custom_1578665619532{padding-top: 60px !important;}&#8221; z_index=&#8221;&#8221;][vc_column width=&#8221;1\/2&#8243;][vc_column_text]Smart FoIP, Commetrex\u2019 patented technology, has been integrated&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":98,"menu_order":45,"comment_status":"closed","ping_status":"closed","template":"template-products.php","meta":{"footnotes":""},"class_list":["post-1485","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/pages\/1485","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/commetrex.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1485"}],"version-history":[{"count":9,"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/pages\/1485\/revisions"}],"predecessor-version":[{"id":5685,"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/pages\/1485\/revisions\/5685"}],"up":[{"embeddable":true,"href":"https:\/\/commetrex.com\/index.php?rest_route=\/wp\/v2\/pages\/98"}],"wp:attachment":[{"href":"https:\/\/commetrex.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1485"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}