Abstract:
Method and system for providing ad-splicer N+1 redundancy in a network by employing TIP network intelligence &amp; techniques to facilitate a redundant ad-splicer presuming, within few seconds, the functionality of the failed primary ad-splicer. The network triggers the installation of unlist and multi cast route on an interface by tracking one or more unlist routes to deliver the unlist and (pre-spliced) multi cast traffic to the redundant ad-splicer. The network dynamically adjusts the multi cast trees to continue to deliver the post-spliced multi cast traffic to the intended receivers.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to data network management. More specifically, the present invention relates to methods and system for providing network based provisions of N+1 redundancy for ad splicer in an TIP/MILS network such as cable/multiple service operator (MOS) network or in a wireline network. 
       BACKGROUND 
       [0002]    In a typical cable/MOS network, ad splicer plays a significant role due to its ability to splice the advertisements or commercials into the live video streams using analog or Digital Program Insertion (DIP). More specifically, an ad server typically stores the commercial content and streams it to the ad splicer when triggered by digital cues. Using digital ad insertion standard such as DES 253 (which supports the cable based DIP cubing message) or SATE35, the ad splicer is configured to splice the MPEG commercial video streams into the programmer&#39;s digital streams. The ad splicer also allows the operator to select among multiple programmer video streams, providing outputting signal carriage of only those networks carried by the operator. 
         [0003]    A single market may typically have as many as 40 different advertisement zones which may be demographically grouped areas of a market that receive the same advertising content. A single hub in the network may be configured to serve multiple advertisement zones. Since each ad splicer serves a single advertisement zone, a hub with multiple advertisement zones includes a set of ad splicers for each advertisement zone. 
         [0004]    Video and content service providers have relied upon the ad splicer capability to insert the appropriate advertisements or commercials into the live video streams as a substantial revenue source. Thus, ad splicer failure or downtime has significant impact both in real time transmission service disruption as well as loss of potential revenue from advertisements or commercials which do not get transmitted. Indeed, the undesirable mean time to repair such ad splicer failure can range from a few minutes to several hours. 
         [0005]    Present approaches to address ad splicer failure include human intervention where a technician is dispatched to the HUB site to physically move the links from the failed ad splicer to a redundant ad splicer in the HUB site. 
         [0006]    In view of the foregoing, it would be desirable to have methods and systems to improve the overall mean time to repair (MTT) network downtime due to ad splicer failure. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a block diagram of a data and content network such as a regional access network (RAN) for practicing one or more embodiments of the present invention; 
           [0008]      FIG. 2  is a flowchart illustrating the process for providing ad splicer redundancy in a data and content network in accordance with one embodiment of the present invention; 
           [0009]      FIG. 3  is a flowchart illustrating dynamic forwarding of unlist at traffic and pre-spliced multi cast traffic to backup ad splicer of step  220  shown in  FIG. 2  in accordance with one embodiment of the present invention; and 
           [0010]      FIG. 4  is a flowchart illustrating the process for providing ad splicer redundancy in a data and content network in accordance with another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 1  is a block diagram of a data and content network such as a regional access network (RAN) for practicing one or more embodiments of the present invention. Referring to  FIG. 1 , a regional access network (RAN)  100  includes a HUB site  110  configured with a primary router  111  coupled to a primary ad splicer  112 . The primary router  111  is also connected to a plurality of receivers such as broadcast QAM  113  in the HUB site  110 , each of which are connected to the hybrid fiber coax (HFC)  114 . As shown in the  FIG. 1 , the primary router  111  is coupled to the TIP cloud/date network  160  to receive and/or transmit data. 
         [0012]    Referring to  FIG. 1 , the router  111  is also coupled to the TIP cloud/data network  160  in the network  100  for communication a content source terminal  130  and the ad server  140 , and configured to receive the pre-spliced multi cast traffic and the ad traffic, respectively, from routers  121  and  150 , for example, over the TIP could/data network  160  as shown in the Figure. Also shown in  FIG. 1  is a second HUB site  120  including the router  121  and redundant ad splicer  122 . Within the scope of the present invention, the second HUB site  120  with the router  121  and the redundant ad splicer  122  may be configured to support multiple HUB sites in the regional access network  100 . 
         [0013]    More specifically, in one embodiment of the present invention, when the ad splicer  112 , which is configured to receive and transmit multi cast traffic, fails, the router  111  that is directly connected to the ad splicer  112  is configured to withdraw the route to the ad splicer  112  from the Interior Gateway Protocol (IGP). Upon the IGP convergence, the router  121  that is connected to the redundant ad splicer  122  is configured to route the unlist traffic which was intended for the failed ad splicer  112  and includes the ad traffic and the pre-spliced multi cast traffic, to the redundant ad splicer  122 . In one embodiment, the redundant ad splicer  122  is configured to splice the incoming unlist traffic routed by the router  121 , and to transmit the post-spliced multi cast traffic to the router  121 . Thereafter, the post spliced traffic is delivered to the intended QAM  113  via the router  111 . 
         [0014]    Referring back to  FIG. 1 , in one embodiment of the present invention, using Protocol Independent Multi cast—Source Specific Multicasting (PIM-SSM), the router  111  is configured to build the source—group (S, G) tree to router  121  which is connected to the redundant ad splicer  122  substantially immediately after the IGP convergence as the route to the source S is available via router  121 . Thus, the post spliced traffic may be delivered to the QAM  113  via the router  111 . Referring again to  FIG. 1 , in the case where Protocol Independent Multi cast in Sparce Mode (PIM-SM) is used in the network  100 , the router  121  is configured to register with the rendezvous-point (RP) upon receiving the post spliced multi cast traffic from the redundant ad splicer  122 . The rendezvous point (RP) is then configured to build the source—group (S, G) to the router  121  to receive the multi cast traffic natively. Thus, the post spliced traffic is then appropriately delivered to the QAM  113  via the router  111 . 
         [0015]    The multi cast routers such as routers  111 ,  121 , and  150  are configured to maintain the state regarding the incoming and outgoing interfaces for each source—group (S, G) pair. The maintained state is used to determine which data packets are to be discarded and which are to be forwarded. The state information is maintained in a multi cast routing table by each multi cast router  111 ,  121 ,  150 , where each entry in the multi cast routing table corresponds to a unique source—group (S, G) pair referred to as mroute, each mroute containing four types of entries—(1) address of the multi cast group, (2) address of the corresponding source, (3) the incoming interface, and (4) a list of outgoing interfaces. 
         [0016]    Referring back to  FIG. 1 , in one embodiment of the present invention, the redundant ad splicer  122  is connected to the router  121  in the network  100  via an interface namely gig1/1, and provisioned with an enhanced mapping table. More specifically, the redundant ad splicer  122  in one embodiment is configured to accept multi cast traffic (S1, G1) intended for the primary ad splicer  112  without sending out an (S1, G1) IGMP join on the interface gig1/1 to the router  121 . Upon receiving the multi cast traffic (S1, G1), the redundant ad splicer  122  is configured to splice the pre spliced multi cast traffic, and generate to post spliced multi cast traffic with (S2, G2) TIP addresses. The (S2, G2) TIP address is obtained through the pre-defined mapping table which is maps or associates the incoming pre spliced traffic (S1, G1) to the TIP address of the outgoing multi cast traffic (S2, G2). 
         [0017]    The router  121  is configured with the floating unlist static routes with the next hop as the gig1/1, with admin distance of 254, for example. In one embodiment, the floating unlist static routes include the TIP addresses of the ad splicers receiving the ad traffic. More specifically, each static route is destined to an TIP address of the primary ad splicer  112  that is configured to receive the pre-spliced multi cast traffic for one or more Group addresses (including G1). For example, in one embodiment of the present invention, the floating static route may be configured on router  121  as follows: 
         [0018]    router (conf)#ip route &lt;S1&gt; gig1/1 254 
         [0019]    router (conf)#ip route &lt;S2&gt; gig1/1 254 
         [0020]    where S1 represents the IP address used by the primary ad splicer to receive the ad traffic, and further, where S2 represents the IP address used by the primary ad splicer as the source IP address of the post spliced multi cast traffic. 
         [0021]    In this manner, as described above, in one embodiment of the present invention, the floating unlist static route is installed in the routing table of the router  121  connected to the redundant ad splicer  122  (and other routers in the network) if the IGP learned routes to the IP addresses S1, S2, respectively, are not available, for example, in the event of the ad splicer  112  failure. 
         [0022]    Referring again to  FIG. 1 , the router  121  in one embodiment of the present invention is also configured with an artificially high metric value, which is close to maximum, such as “15555555” in case of OSPF or “3294967295” in case of ISIS, for example, so that the devices and terminal connected to the network  100  do not prefer the path to the router  121 . That is, when the primary ad splicer  112  returns back to functional service in the network  100 , the IGP converges, and each network device immediately starts using the primary ad splicer  112 . For example, in one embodiment of the present invention, the Router  121  may be configured with “redistribute static metric 15555555” within the IGP (that is, Open Shortest Path First (OSPF) or Intermediate System to Intermediate System (ISIS)). This configuration is provided so that the devices connected to the network  100  prefer the routes to the primary ad splicer  112 , if available and functional. In one embodiment, the following routine may be used to configure Router  121 : 
         [0023]    router ospf 1 
         [0024]    redistribute static metric 15555555 
       In another embodiment, the following routine may be used to configure Router  121 : 
       [0025]    router isis 
         [0026]    redistribute static ip metric 3294967295 
         [0000]    It is to be noted that while 15555555 is used in the description above to represent an artificially high metric value, other artificially high values may be used (where the highest value being 0×FFFFFE=16777214), such that routes to the primary ad splicer  112  is always preferred in the network  100  by the network devices if the primary ad splicer  112  is available. 
         [0027]    Referring still to  FIG. 1 , in the manner described above, in one embodiment of the present invention, router  121  may be configured to dynamically inject the reverse mroute when the primary ad splicer  112  fails. That is, in one embodiment, during the primary ad splicer  112  failure, the router  121  connected to the redundant ad splicer  122  is configured to dynamically assign the static Internet Group Management Protocol (IGMP) group membership to the redundant ad splicer  122 . A terminal or device in the network  100  may transmit a IGMP membership report message to join a multi cast group, where the IGMP is common to all multi cast router protocols, and isolates end users from the routing protocol in use. 
         [0028]    In this manner, during the time period when the primary ad splicer  112  is in failure mode, the redundant ad splicer  122  may be configured to receive the relevant pre-spliced traffic intended for the primary ad splicer  112  so that the network  100  may be configured to dynamically modify the delivery of the pre-spliced traffic to the redundant ad splicer  122  during primary ad splicer  112  failure, and to deliver the post spliced traffic to the intended receivers such as QAMs  113  during the primary ad splicer  112  failure. 
         [0029]    In this manner, within the scope of the present invention, one redundant ad splicer  122  may be configured to back up more than one ad splicer in the various HUB sites in the regional access network. In addition, overall mean time to repair (MTT) may be substantially improved by configuring the network  100  to converge and dynamically provide the redundancy, in addition, to obviating the need for on-site repair at the HUB site of the failed ad splicer. 
         [0030]      FIG. 2  is a flowchart illustrating the process for providing ad splicer redundancy in a data and content network in accordance with one embodiment of the present invention. Referring to  FIGS. 1 and 2 , in normal operation, the primary ad splicer  112  is configured to receive the pre spliced multi cast traffic for (S1, G1) and to generate the corresponding post spliced (S2, G2) multi cast traffic after splicing it. The primary ad splicer  112  in this functional mode is configured also to receive the ad traffic using the S1 source address to reference itself 
         [0031]    Referring now to  FIG. 2 , at step  210  the primary ad splicer failure  112  is detected. Thereafter, at step  220 , in one embodiment of the present invention, the unlist ad traffic and the pre spliced multi cast traffic is dynamically forwarded to the redundant or backup ad splicer  122  ( FIG. 1 ). As discussed above, the redundant ad splicer is configured with the enhanced mapping table to support the network traffic in the event of the primary ad splicer  112  failure. That is, in one embodiment, the router  121  connected to the redundant ad splicer  122  is configured to dynamically inject an mroute to the routing table of the redundant as splicer  122 . In this manner, when the primary ad splicer  112  failure is detected, the network  100  is configured to dynamically route the unlist traffic and the pre spliced multi cast traffic to the redundant ad splicer  122 . 
         [0032]    Referring back to  FIG. 2 , after splicing the traffic, the post spliced multi cast traffic including ad traffic is provided to the router  121  connected to the redundant ad splicer  122 , and at step  230 , the router  121  is configured to transmit the spliced multi cast traffic and the ad traffic to the intended or target receivers (for example, the QAMs  113 ) in the network  100 . Thereafter, at step  240  it is determined whether the primary ad splicer  112  ( FIG. 1 ) has returned to operational mode from its failed status. If at step  240  it is determined that the primary ad splicer  112  is not operational, then the routine returns to step  220 , and continues to dynamically forward the unlist ad traffic and the pre spliced multi cast traffic to the redundant ad splicer  122  ( FIG. 1 ). On the other hand, if it is determined at step  240  that the primary ad splicer  112  has returned from its failure mode and is once again operational, then at step  250 , the unlist ad traffic and the pre spliced multi cast traffic is re routed to the primary ad splicer  112  as intended, and the redundant ad splicer  122  withdraws. For example, as discussed above in conjunction with  FIG. 1 , the router  121  directly connected to the redundant ad splicer  122  is configured with an artificially high metric values within the IGP so that each network device or router in the network  100  is configured to prefer the routes to the primary ad splicer  112  when the primary ad splicer  112  is operational. 
         [0033]    Referring still to  FIG. 2 , while the determination of whether the primary ad splicer  112  ( FIG. 1 ) is identified as step  240  in the routine described above, within the scope of the present invention, the network  100  may be configured such that the operational mode of the primary ad splicer  112  from a failure mode is continuously monitored. Alternatively, the primary ad splicer  112  may be configured to broadcast its operational status upon exiting the failure mode and enters the network  100  such that the ad traffic and the pre-spliced multi cast traffic intended for the primary ad splicer  112  are provided to the primary ad splicer  112  when it is operational. 
         [0034]      FIG. 3  is a flowchart illustrating dynamic forwarding of unlist at traffic and pre-spliced multi cast traffic to backup ad splicer of step  220  shown in  FIG. 2  in accordance with one embodiment of the present invention. Referring to  FIG. 3 , in one embodiment of the present invention, at step  310 , the router  121  connected to the redundant ad splicer  122  through a gig1/1 interface, for example, is provisioned with enhanced mapping table. That is, in one embodiment of the present invention, router  121  is configured to accept the multi cast traffic (S1, G1) even if it did not send out an (S1, G1) IGMP join on the interface gig1/1 to the router  121 . 
         [0035]    Thereafter at step  320 , the floating unlist static routes to router  121  are installed at step  320 . As discussed above, the floating unlist static routes installed in the routing table of router  121  include, for example, IP addresses of the primary ad splicer  112  that is configured to receive the ad traffic. Referring back to  FIG. 3 , after installing the floating unlist static routes to the routing table of router  121  connected to the redundant ad splicer  122 , at step  330  the artificially high static metric is installed within the interior gateway protocol (IGP) to the Router  121 . This configuration allows the ad traffic and the pre spliced multi cast traffic to be re-routed to the primary ad splicer  112  when it becomes operational and exits the failure mode. Thereafter, at step  340 , the static mroute with outgoing interface OIF of the redundant ad splicer  122  is installed in the Router  121 . 
         [0036]    When the primary ad splicer  112  failure is detected, the router  111  which is directly connected to the primary ad splicer  112  withdraws the routes to the primary ad splicer  112  from the IGP. After the IGP converges, router  121  is configured to install the floating static route to the redundant from its routing table and to redistribute the floating static route into the IGP with the artificially high metric value. In this manner, the router  121  may in one embodiment be configured to substitute the redundant ad splicer  122  for the failed primary ad splicer  112  such that, the devices and terminals in the network  100  including the router  111  at the HUB Site  110  ( FIG. 1 ) considers the primary ad splicer  112  reachable through the router  111  (even though the primary ad splicer  112  is in the failure mode). 
         [0037]    In turn, the ad traffic intended for the primary ad splicer  112  is routed to the redundant ad splicer  122  based on the floating static route installed in the routing table and redistribution of the installed floating static route into the IGP with the source traffic IP address (S1) including, for example, the source IP address of the pre spliced multi cast traffic and the ad splicer IP address for the ad traffic. In addition, the router  121  is configured to install the static mroute with OIF as gig1/1 as discussed above, such that the IGMP static join for destination group G1 to be assigned to the interface specified gig1/1. Thus, the router  121  is configured to forward the pre spliced multi cast traffic (S1, G1) over the gig1/1 interface to the redundant ad splicer  122 . In turn, the redundant ad splicer  122  is configured to process the incoming multi cast traffic for (S1, G1), splices it, and transmits the post spliced traffic (S2, G2) back to the router  121  connected via the interface gig1/1. 
         [0038]    Moreover, router  121  is configured with the associated rendezvous point (RP) mapping (for example, in the case of PIM-SM) for the destination group G2, and starts the PIM-SM registration process with the RP which, in this example, is the router  111  connected to the failed primary ad splicer  112 . Thereafter, the multi cast traffic is transmitted over the source tree as soon as the source tree is built, such that, the rendezvous point (RP) for router  121  allows the post spliced multi cast traffic and the ad traffic on the shared tree to the intended receivers such as the QAM  113 , where the shared tree (or cored based tree) is the set of paths from the RP to the complete set of group members or receivers. 
         [0039]    Alternatively, in the case where PIM-SSM is deployed, the Router  111  is configured to build the source—group (S, G) to the router  121  substantially immediately after the IGP convergence, in which case, the router  121  puts the received multi cast traffic on the source tree for the appropriate delivery to the intended receivers QAM  113 . 
         [0040]    In this manner, in one embodiment of the present invention, the router  121  directly connected to the redundant ad splicer  122  may be configured to dynamically route the unlist ad traffic and the pre spliced multi cast traffic to the redundant ad splicer  122  when the primary ad splicer  112  fails, by for example, dynamically assigning the static IGMP group membership to the redundant ad splicer  122  by injecting the reverse mroute in the event of primary ad splicer  122  failure. 
         [0041]    When the primary ad splicer  112  recovers from the failure mode, the Router  111  is configured to start advertising the route to the primary ad splicer  112  in its IGP. The IGP advertisement, in turn, causes the network  100  to prefer the path to the primary ad splicer  112 , and remove the path advertised by router  121  directly connected to the redundant ad splicer  122 . In addition, the router  121  is configured to remove the floating static route previously installed in the IGP since an IGP route with admin distance less than 250) is available (i.e., to the primary ad splicer  112 ). In this manner, the redundant ad splicer  122  may be freed up for subsequent backup use, and the primary ad splicer  112  may be placed back into the service. 
         [0042]      FIG. 4  is a flowchart illustrating the process for providing ad splicer redundancy in a data and content network in accordance with another embodiment of the present invention. Referring to  FIG. 4 , at step  410  the router directly connected to the redundant ad splicer in the network is configured for multi cast reverse route injection. Thereafter at step  420 , enhanced mapping table is provided to the redundant ad splicer to generate outgoing post spliced multi cast traffic without sending any IGMP join. When the primary ad splicer failure is detected at step  430 , a unlist route towards the redundant ad splicer is dynamically injected and the ad traffic is forwarded to the redundant ad splicer at step  440 . Then, at step  450 , the reverse mroute is dynamically injected by assigning static IGMP group membership to the redundant ad splicer. Thereafter, at step  460  the pre-spliced multi cast traffic is spliced and the post spliced multi cast traffic and the unlist ad traffic is transmitted to the intended receivers in the network. 
         [0043]    Referring back to the Figures, when the primary ad splicer  112  connected to router  111  fails, the router  121  directly connected to the redundant ad splicer  122  is configured to dynamically assign the IGMP membership to a specified interface, for example, the Gigabit Ethernet interface gig1/1 without receiving an IGMP report on that interface gig1/1. More specifically, the router  121  may be configured to dynamically inject an mroute without a specified OIF in the mrouting table when a predefined event occurs, for example, when a specific static unlist route (with or without the tag value) is installed in the routing table. In this manner, in one embodiment of the present invention, multi cast reverse route injection may be performed based on the installation of the unlist static route. For example, the multi cast reverse route injection may be performed by expanding the existing static route to associate the unlist and multi cast static routes, or by performing IPPS—IGMP policy propagation using static routing, as discussed in further detail below. 
         [0044]    In the case where the multi cast reverse routing injection is performed by expanding the existing static route to associate the unlist and the multi cast static routes, each static route may be expanded to incorporate the static mroute as illustrated by the following: 
         [0045]    ip route&lt;primary ad splicer  112  IP address&gt;gig1/1 254 inject &lt;G1 or S1, G1&gt; 
         [0000]    where the “inject” above is provided as a sample knob to inject the *, G, or S, G entry in the mrouting table with the gig1/1 as the outgoing interface (OIF). 
         [0046]    Alternatively, as discussed above, the multi cast reverse routing injection may be performed by IPPS—IGMP policy propagation using static routing. That is, the existing unlist static route CLI is retained and a tag value is used within the floating static route to install the static mroute. In other words, when a unlist static route with a predetermined tag value becomes available, the IGMP membership is triggered so that the IGMP Group membership is dynamically assigned. 
         [0047]    Accordingly, within the scope of the present invention, there is provided a redundant and/or backup ad splicer that may be configured to assume the role of the failed ad splicer in the network by receiving both the advertisement traffic, and the pre-spliced multi cast content from the network, and to transmit the post spliced traffic including the post spliced multi cast traffic and the ad traffic back to the network for transmission to the target receivers in the network. Accordingly, in one embodiment, the IP network may be configured to be dynamically modified to re-route the pre-spliced traffic to the backup ad splicer from the failed ad splicer path, and to deliver the post spliced traffic to the target receivers such as QAM during the time period when the failed ad splicer is not functioning. 
         [0048]    More specifically, in one embodiment, an mroute with a specified OIF may be configured to be dynamically injected in the mrouting table when a predetermined event occurs, such as based on the installation of a specific static unlist route in the routing table. That is, as discussed above, the IGMP Group membership may be dynamically assigned to a specified interface (such as the interface between the backup ad splicer and the router directly connected to the backup ad splicer) based on the predetermined event occurrence without any IGMP report on the specified interface. 
         [0049]    In the manner described above, in accordance with the various embodiments of the present invention, there are provided methods and systems to minimize or avoid requirement of on-site repair, installation of a redundant ad splicer in every HUB site, reduce the end to end service disruption due to ad splicer failure to substantially less than one minute, and further, to improve the overall mean time to repair (MTT) network downtime due to ad splicer failure by providing dynamic ad splicer redundancy. 
         [0050]    Moreover, in accordance with the various embodiments of the present invention, a single ad splicer may be configured to back up more than one ad splicer for multiple HUB sites, providing equipment cost effectiveness and efficiently. In addition, IP routing protocols such as IGP and PIM may be used to implement the network based ad splicer redundancy to increase operational efficiency and take advantage of the benefits derived from the IP routing protocols. 
         [0051]    A method of providing ad splicer redundancy in a network in one embodiment of the present invention includes monitoring an availability of a first ad splicer, dynamically forwarding a unlist and a multi cast traffic intended for the first ad splicer to a second ad splicer, receiving a post spliced multi cast traffic, and transmitting the post spliced multi cast traffic to one or more target receivers. 
         [0052]    In one aspect, monitoring the availability of the first ad splicer may include detecting a first ad splicer failure on a first routing device, and detecting an installation of a predetermined unlist routing information. 
         [0053]    In another aspect, dynamically forwarding the unlist traffic may include configuring a floating unlist static route towards the second ad splicer with a predetermined static metric value, where floating unlist static route may include an Internet Protocol (IP) address of the first ad splicer, and further, where the predetermined static metric value may include an artificially high static metric value. 
         [0054]    In yet another aspect, dynamically forwarding the pre-spliced multi cast traffic may include injecting one or more reverse mroutes towards the second ad splicer. 
         [0055]    Moreover, injecting the reverse mroute may include assigning a static Internet Group Management Protocol (IGMP) group membership to an interface coupling the second ad splicer. 
         [0056]    In still another aspect of the present invention, the method may also include detecting an operational mode notification of the first ad splicer, withdrawing a reachability information of the first ad splicer, and triggering an installation of a floating static route to the first ad splicer. 
         [0057]    A method of providing ad splicer redundancy in a network in another embodiment of the present invention includes detecting a failure mode of a first ad splicer, installing a floating static route towards a second ad splicer, forwarding a unlist traffic to the second ad splicer, forwarding pre spliced multi cast traffic to the second ad splicer, receiving a corresponding spliced multi cast traffic from the second ad splicer, and transmitting the post spliced multi cast traffic to one or more receiver terminals. 
         [0058]    The unlist traffic may include advertisement traffic. 
         [0059]    In one aspect, transmitting the post spliced multi cast traffic may include sending the post spliced multi cast traffic on a shared or source tree to the one or more receiver terminals. 
         [0060]    In a further aspect, the method may also include detecting an operational mode notification of the first ad splicer, withdrawing a reachability information of the first ad splicer, and triggering an installation of a floating static route to the first ad splicer. 
         [0061]    An apparatus in yet another embodiment of the present invention includes a network interface, one or more processors coupled to the network interface, and a memory storing instructions which, when executed by the one or more processors, causes the one or more processors to detect a failure mode of a first ad splicer, dynamically forward a unlist and a multi cast traffic to a second ad splicer via the network interface, and receive a post spliced multi cast traffic from the second ad splicer via the network interface. 
         [0062]    The memory may be further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to transmit the post spliced multi cast traffic over the data network. 
         [0063]    In one aspect, the memory may be further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to detect the failure mode of the first ad splicer on a first routing device operatively coupled to the first ad splicer. 
         [0064]    The memory in another aspect may be further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to install a floating unlist static route towards the second ad splicer with a predetermined static metric value, where the floating unlist static route may include an Internet Protocol (IP) address of the first ad splicer, and further, where predetermined static metric value may include an artificially high static metric value. 
         [0065]    The memory may be further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to inject one or more reverse mroutes towards the second ad splicer. 
         [0066]    In yet another aspect, the memory may be further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to assign a static Internet Group Management Protocol (IGMP) group membership to an interface coupling the second ad splicer. 
         [0067]    The network interface may include a router. 
         [0068]    An apparatus in accordance with still another embodiment of the present invention includes a network interface, one or more processors coupled to the network interface, and a memory storing instructions which, when executed by the one or more processors, causes the one or more processors to install a floating static route towards a second ad splicer, forward a unlist traffic and pre spliced multi cast traffic to the second ad splicer via the network interface, and receive a corresponding spliced multi cast traffic from the second ad splicer via the network interface. 
         [0069]    The memory is further configured for storing instructions which, when executed by the one or more processors, causes the one or more processors to send the post spliced multi cast traffic on a shared or source tree to the one or more receiver terminals. 
         [0070]    A system for providing ad splicer redundancy in a network in accordance with still another embodiment of the present invention includes means for detecting a failure mode of a first ad splicer, means for dynamically forwarding a pre-spliced traffic for the first ad splicer to a second ad splicer, means for receiving a post spliced multi cast traffic, and means for transmitting the post spliced multi cast traffic. 
         [0071]    The various processes described above including the processes performed by the routers  112 ,  121  in the software application execution environment in the network  100  including the processes and routines described in conjunction with  FIGS. 2-4 , may be embodied as computer programs developed using an object oriented language that allows the modeling of complex systems with modular objects to create abstractions that are representative of real world, physical objects and their interrelationships. The software required to carry out the inventive process, which may be stored in the memory (not shown) of the routers  112 ,  121 , may be developed by a person of ordinary skill in the art and may include one or more computer program products. 
         [0072]    Various other modifications and alterations in the structure and method of operation of this invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. It is intended that the following claims define the scope of the present invention and that structures and methods within the scope of these claims and their equivalents be covered thereby.