Patent Application
20090003231
In a packet switched network, an end-to-end connection bearing various media services (e.g., voice, video) may be transmitted in the “data plane” by one or more bearer flows, each of which being composed of a packet stream. Collectively, these bearer flows span the end-to-end connection. As such, packet switching elements located along a connection path utilize standard packet switching protocols within the data plane to interconnect composite bearer flows.
Furthermore, an end-to-end connection along with its composite bearer flows are established in accordance with standard signaling protocols (e.g., Session Initiation Protocol (SIP)) conveyed across the “control plane” between the connection endpoints. Within this control plane, a connection controller typically acts as an intermediate signaling agent in directing the establishment of the data plane resident bearer flows supporting the requested connection.
Signaling pursuant to the establishment of an end-to-end connection is typically initiated via an originating node's transmission of a “connection set-up” message (e.g., a SIP INVITE message) to the control plane indicating the address of the intended destination node along with the originating node's selection of various connection attributes. These connection attributes typically include the originating node's selection of various call parameters, along with its selection of the originating node's address parameters to be utilized by subsequent bearer flows. This “connection set-up” message is propagated through one or more intermediary signaling agents via the control plane's underlying packet switching network (again using standard packet switching protocols), and ultimately to the addressed destination node. At this point, the destination node may signal its response to the originating node to the “connection set-up” message indicating its preferred selection of various call parameters, inclusive of the destination node's selection of address parameters to be utilized by data plane resident bearer flows to be subsequently sent to it. In this fashion, the originating and terminating nodes along with intervening signaling agents communicate within the context of the control plane to not only “negotiate” various call parameters, but to establish the composite bearer flows that will subsequently transport the end-to-end connection's media within the data plane.
In many networks, especially wireless networks, service providers are motivated to monitor the connections of its subscribers and to offer differentiating services that not only attract new subscribers, but also provides leverage in preventing churn among existing subscribers. One such set of differentiating services are pertinent in the area of Media Quality Enhancement (MQE). The implementation of these sorts of services within a service provider's network typically requires the application of intermediate media processing functionality somewhere along the path of an end-to-end connection between subscribers.
A method or corresponding apparatus in an example embodiment of the present invention transparently monitors signaling messages traversing the “control plane” for the establishment of prospective “data plane” resident connections bearing media types which are to be targeted for intermediate media processing between the connection end nodes. In an example embodiment, the method or corresponding apparatus utilizes Policy Based Routing (PBR) to direct signaling messages from a routing point within the control plane to a signaling monitoring point, also within the control plane. This signaling monitoring point acts as an intermediate signaling agent which first identifies the connection set-up signaling pursuant to the establishment of data plane connections with the media types targeted for media processing. Once so identified, this signaling agent substitutes for the bearer flow address information contained in the signaling messages with bearer flow address information of media processing points in the data plane network such that subsequent bearer flows are directed to the selected media processing points. Once such bearer flow address information has been substituted into the original signaling message, the modified signaling message is presented by the signaling agent back to the control plane's packet switching network, at which point the modified signaling message is forwarded to its original destination by Destination Based Routing (DBR) capabilities inherent to the control plane network.
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
A description of example embodiments of the invention follows.
In today's network, enhancing, processing, or otherwise modifying signals in bearer flows in or at equipment already deployed in a network may be done by modifying or upgrading existing equipment, or otherwise invasively routing signals through identified network elements. In accordance with embodiments of the present invention, control plane signaling is intercepted and transparently monitored using policy based routing to direct connection control signals from a routing point in the control plane to a monitoring point also residing in the control plane. As such, fields contained in the headers of protocols (e.g., at layers 2, 3, and 4) utilized to transport the subject connection control protocol (e.g., Session Initiation Protocol (SIP)) remain unchanged while at the signaling monitoring point in order that the connection control signal may be ultimately forwarded on to its original destination via normal destination based forwarding across routing points within the control plane. While at the signaling monitoring point, addressing parameters of a selected media processing point residing in the data plane is substituted for the data plane addressing parameters originally contained in the connection set-up signal. This causes subsequent bearer flows to be directed to the selected media processing point from a routing point within the data plane by destination based routing once the connection is established. At the time that the media processing point's address substitution occurs, the signaling monitoring point also notifies the selected media processing point of the original data plane address parameters for which substitution occurred. This is so that the media processing point, once it has processed the media contained in a redirected bearer flow, may forward the enhanced media in a bearer flow to its original destination as specified in the original signaling message. Once the signaling monitoring point is through with the connection control signal, the signal (containing its pertinent bearer flow addressing substitutions) is forwarded to its original destination.
In example embodiments of the invention, bearer flows may be directed (as described above) to a media processing point to process encoded media on the bearer flows to monitor metrics associated with the media and/or bearer flows. In other example embodiments of the invention, bearer flows may be directed to a media processing point (again, as described above) to apply media enhancement (e.g., Coded Domain-Media Quality Enhancement (CD-MQE)) to encoded media to produce an enhanced encoded media. In some embodiments of the invention, the bearer flows may be selectively directed to a media processing point depending on the identity of either the sending or receiving party, their service subscriptions, or specific media types. Furthermore, some example embodiments of the invention may be used either within or outside of a single Mobile Telephone Switching Office (MTSO) in Local Access, Backhaul, or Wide Area networking applications.
Before describing specific example embodiments of the present invention in reference to
The MTSO 101 may include a number of typical networking elements, including cross connect switches 120, aggregation routers 130, and Ethernet switches 140 by which traffic transmitted across multiple backhaul networks 115 and 185 is aggregated towards or distributed from a mobile switching center 150 (MSC). Connections from a mobile device (not shown) served by the local MTSO can be made through the MSC 150 to another mobile device served by the same MTSO 101, to a mobile device served by another MSC in another MTSO 170, or to a landline through the public switched telephone network 175 (PSTN). The MSC 150 may provide a number of services, including mobility management for subscribers (e.g., registration, authentication, authorization for services), media conversion (TDM to packet gateway, media transcoding), and signaling (signaling gateway, signaling transport, connection control). Connection control services determine how connections are set-up and support bearer flows routed to carry the media traffic within the same MTSO 101, to another MTSO 170, or to the PSTN 175. As shown, the PSTN may connect with any number of different MTSOs 101.
Once connection control services have established a connection between mobile devices, the supporting bearer flows may travel through either an “intra-MTSO” or “inter-MTSO” data path. Bearer flow 102 illustrates a connection between mobile devices on base transceiver stations 110 served by the same MTSO 101, also referred to as an intra-MTSO signal flow. Following bearer flow 102, the bearer flow is sent through the base transceiver station 110 through the T1 backhaul 115 to a digital cross connect 120 in the MTSO 101. At the MTSO 101, the bearer flow 102 is directed by a router 130 to an Ethernet switch 140 to the MSC 150. The MSC 150 sends the connection to a multilayer switching (MLS) device 160. At the MLS 160, the Intra-MTSO bearer flow is routed back to the MSC 150 from which the bearer flow traverses the reverse direction across the Ethernet switch 140, router 130, cross connect 120, across the T1 backhaul 115, and on to the destination base transceiver station 110 corresponding to the destination mobile device (not shown in
Bearer flow 104 illustrates a connection between mobile devices on base transceiver stations served by the different Mobile Telephone Switching Offices, MTSO 101 and MTSO 170; the bearer flow 104 is also referred to as an inter-MTSO connection. The bearer flow 104 is similar to the intra-MTSO flow up until the signal reaches the MLS 160. At the MLS 160, however, the bearer flow 104 is routed through an external network, such as an Internet Protocol Wide Area Network (IP WAN) 165, to an MSC (not shown) in another MTSO 170 with which the destination mobile device (not shown) is associated.
As discussed earlier, service providers may be motivated to offer differentiating services requiring additional processing on various media types (e.g., voice, video). Towards this end intermediate network elements may be introduced to (1) monitor connection control signaling operating in the control plane for the establishment of connections bearing targeted media types and (2) to direct the bearer flows transporting these targeted connections to media processing points in the network where differentiated services can be applied.
Whether monitoring connection control signaling within a control plane or providing media processing services directly on bearer flow payloads, service disruption due to nodal failure of elements operating in either the control or data planes is preferably avoided. Further, the deployment of new systems into the control or data planes of networks employing legacy products adds further complexities in the form of additional interoperability criteria as well as increased network operational cost. In accordance with example embodiment(s) of the present invention, these concerns are addressed in an unobtrusive and transparent manner allowing for seamless integration as illustrated in
Packets directed from or towards the MSC 250 via the network flows 204, 205 are routed to/from the Media Server 290 using either policy based routing or destination based routing functions on the MLS 260. Policy based routing is utilized for signaling flows arriving at the MLS 260 from either the MSC 250 or the IP WAN 265. Destination based routing is utilized for signaling flows arriving at the MLS 250 from the Media Server 290 and for bearer flows arriving from either the MSC 250 or the IP WAN 265. As such, policies may be employed by the MLS 260 to act autonomously on the signaling flows to “transparently” integrate the Media Server 290 into the control plane. Thus, the packets contained within these signaling flows are not directly addressed to the Media Server 290, but rather, the Media Server 290 “picks up” the packets contained with these signaling flows in a manner “transparent” to the connection endpoints (e.g., the origination and destination MSC's). The Media Server 290 may then modify these signaling packets to cause subsequent bearer flows to be directly sent to itself. As such, the Media Server 290 monitors signaling flows for certain connection set-up messages for targeted connections containing specific parameters (e.g., targeted media subtypes). Once a target connection has been so identified, the Media Server 290 modifies the set-up message pursuant to that connection to “draw” subsequent bearer flows carrying the target media for that connection to itself. Once so modified, these the packets containing these signaling message are presented back to the MLS 260, where they will be routed via destination based routing to their original destination—this by virtue of the fact that the original destination's addressing information has remained intact with the encapsulating packet. Note that the use of policy based routing ensures the continuity and reliability of signaling transmission across the control plane. In the event that the Media Server 290 experiences any sort of fault condition affecting its transmission links by which it connects to the MLS 260, the MLS 260 will not employ its configured policy based routing rule set, but, instead, defaults to destination based routing capabilities inherent to the MLS 260. Thus, the control plane packets “bypass” the faulted Media Server 290 altogether.
Subsequent to connection set-up, associated bearer flows arriving at the Media Server 290 may have their encoded media processed and/or modified by the Media Server 290 for the application of media enhancement services. Once so processed, these “enhanced” bearer packets are re-addressed and sent via the MLS 260 to their original connection endpoint as specified and whose packet addressing information was stored during the original connection set-up proceedings by the Media Server 290. This connection endpoint may be resident either locally in the MTSO 201 co-located MSC 250 or remotely on another MSC contained in a remote MTSO 270 located across the IP WAN 265. This technique can be applied to legacy networks and future networks.
In view of the foregoing, an example embodiment of the present invention includes a method or corresponding apparatus, or some combinations thereof, of transparently monitoring targeted bearer flows. The example method includes directing control plane signals according to policy-based routing associated with the control plane signals through a routing point in a network to a signaling monitoring point in the network. The example method also includes substituting bearer plane address information of a selected media processing point for bearer plane address information in the control plane signal in a manner causing subsequent bearer flows associated with the control plane signal to be directed to the selected media processing point from the routing point by destination based routing.
The method may also include directing bearer flows to a media processing point to process and encode a media signal on the bearer flows to monitor metrics associated with the encoded media signal. This example embodiment may further include adding information based on the metrics to produce an enhanced encoded media signal and outputting the enhanced encoded media signal.
The example method may further include directing bearer flows to a media processing point to apply signal enhancement to an encoded media signal on the bearer flows on the media processing point to produce and enhance encoded media signal and output the enhanced encoded media signal. Applying the encoded media signal enhancement may include applying Coded Domain-Media Quality Enhancement (CD-MQE).
The example method may further include selectively directing bearer flows to a media processing point, applying encoded media signal enhancement to a media encoded signal on the bearer flows at the media processing point to produce an enhanced encoded media signal, and outputting the enhanced encoded signal. A method may further include determining an identity of a sending or receiving party of targeted bearer flows, wherein selectively directing the bearer flows is based on the identity of at least one of the parties. Additionally or alternatively, the method may further include determining subscription features of originators of targeted bearer flows, wherein selectively directing the bearer flows is based on the subscription features. Moreover, the method may further include determining subscription features of destinations of targeted bearer flows, wherein selectively directing the bearer flows is based on the subscription features.
Subsequent bearer flows may occur within an Intra-Mobile Telephone Switching Office communications path, or within a communications path contained therein. Alternatively, the subsequent bearer flows may occur within an inter-mobile telephone switching office communications path or communications path contained therein. Policies associated with the control plane may be based on control plane origination or destination information.
It should be understood that subcombinations of the foregoing example methods are also within the scope of some example embodiments, such as substituting bearer plane address information of a selected media processing point for bearer plane information in control plane signals, received based on policy based routing, in a manner causing subsequent bearer flows associated with the control plane signals to be directed to the selected media processing point by destination based routing. In another example embodiment, in addition to the substituting, processing of an encoded or non-encoded media signal on the bearer flows may also be performed. It should be noted that the example embodiments are not limited to those expressly highlighted in this and the foregoing several paragraphs, but may be found expressly and impliedly within the application, drawings, and claims as presented herein.
(410) A control plane signal (e.g., SIP signal) is sent through the network to establish a new end-to-end connection.
(421) In accordance with an example embodiment of the present invention, the control plane signals are intercepted and redirected to a signaling monitoring point according to policies associated with the control plane signals.
(422) At the signaling monitoring point, after identifying a new connection set-up as a media enhancement candidate, data plane addressing parameters of a selected media processing point are substituted for the data plane addressing parameters of the connection endpoint contained in the connection set-up signal. This causes subsequent bearer flows to be directed to the selected media processing point from a routing point within the data plane by destination based routing once the connection is established.
(424) At the time that the media processing point's address substitution occurs, the signaling monitoring point also notifies the selected media processing point of the original data plane address parameters of the connection endpoint that were substituted for. This is so that the media processing point, once it has processed the media contained in a redirected bearer flow, may forward the enhanced media in bearer flow to its original connection endpoint as specified in the original signaling message.
(426) Once the signaling monitoring point is through with the connection control signal, the signal (containing its pertinent bearer flow addressing substitutions) will be forwarded to its original destination.
(430) Once the connection is established, associated bearer flows are routed directly to the selected media processing point at which point media enhancement services are applied to the encoded media. Subsequently, the enhanced encoded media are re-packetized into associated bearer flows for transmission to the connection endpoint whose data plane addressing parameters have previously been stored by the media processing point (per 424).
At this point, the bearer flows from the connection destination 445 to the connection source 440 for the requested connection have been set-up. It is now time to set-up the other half of the requested connection by establishing the bearer flows from the connection source 440 to the connection destination 445. This is essentially the same signaling process (albeit with different SIP messages) in the reverse direction as was utilized to set-up the first half of the connection. Towards this end, the connection destination 445 initiates a control plane signal 486 (e.g., SIP Response) towards the network to respond to the Modified SIP Invite 485 and arrive at the router 450. The router 450 forwards the packet containing the SIP Response 487 using Policy Based Routing (PBR) 475 to the signaling monitoring point 460. The signaling monitoring point 460 substitutes the data plane addressing parameters (i.e., IP Address, TCP/UDP port number) of the selected media processing point 470 for the data plane addressing parameters (i.e., IP Address, TCP/UDP port number) of the connection destination 445 contained in the SIP Response's 487 Session Descriptor. The signaling monitoring point 460 sends a notification 488 to the selected media processing point 470 of the original data plane addressing parameters (i.e., IP Address, TCP/UDP port number) of the connection destination 445 that were substituted for. This is so that the media processing point 470, once it has processed the media contained in a redirected bearer flow 496, may forward the enhanced media in a bearer flow 497 to its original connection destination 445 as specified in the original SIP Response 487. Subsequent to this notification 488, the signaling monitoring point 460 then outputs the Modified SIP Response 489 to the router 450, which forwards the Modified SIP Response 490 via Destination Based Routing (DBR) 476 to its originally intended recipient, the Connection Source 440.
At this point, the data plane bearer flows supporting both directions of the connection between the connection source 440 and the connection destination 445 have been set-up. Media traffic transported by these bearer flows 491, 495 may now commence. Accordingly, the connection endpoints 440, 445 initiate packets within bearer flows 491, 495 towards the router 450, which forwards these bearer flows 492, 496 on to the media processing point 470 via Destination Based Routing (DBR) 476. As discussed previously, the media processing point 470 may provide media enhancement services (e.g., CD-VQE) to the media carried by these bearer flows 492, 496. Subsequently, the media processing point 470 performs a lookup of the data plane addressing parameters (i.e., IP Address, TCP/UDP port number) of the appropriate connection endpoint 440, 445 in order to construct a packet containing the modified media. The media processing point 470 then sends this packet within the Modified Bearer Flow 494, 497 back to the Router 450, which then forwards the Modified Bearer Flow 495, 498 via Destination Based Routing (DBR) 476 to the appropriate connection endpoint 440, 445.
The signaling monitoring point 570 processes the incoming signaling packet 565 and sends out a modified signaling packet 575. Within the Session Descriptor of the SIP message 565, the signaling monitoring point 570 replaces the connection source's 560 data plane IP Address and User Datagram Protocol (UDP) Port Number with data plane addressing parameters of the selected media processing point. Thus, the signaling packet 575 sent from the signaling monitoring point 570 provides the connection destination 580 with the media processing point's data plane IP address and UDP port number to which the connection destination 580 should send its bearer flows. The layers 2, 3, 4, and SIP headers of the signaling packet 565 received by the signaling monitoring point 570 remain unchanged in the headers 575A, 575B, 575C, 575D contained in the signaling packet 575 transmitted by the signaling monitoring point 570. With respect to
The connection destination 580 receives and processes the signaling packet 575, and subsequently sends to the connection source 560 a signaling packet 585 to initiate the other half of the connection in the opposite direction. This signaling packet 585 response traverses the control plane in the opposite direction than did the original signaling packet 565 as initiated by the connection source 560. After being intercepted to the signaling monitoring point 570 via Policy Based Routing per
Furthermore, with respect to
After the connection is established, the connection source 760 sends and receives media bearing packets 764, 788 within bearer flows 775 to and from the media processing point 790b within the Media Server 790 via the MLS 770. Similarly, the connection destination 780 sends and receives media bearing packets 786, 774 within bearer flows 775 to and from the media processing point 790b within the Media Server 790 via the MLS 770. In this example embodiment, the MLS 770 forwards any arriving media bearing packets 764, 786 via a destination based routing module 770b to the media processing point 790b within the Media Server. At the media processing point 790b, the media contained with media bearing packets 764, 786 may be extracted and/or altered prior to sending the modified media via media bearing packets 774, 788 to the respective connection endpoints 760, 780.
Certain aspects of the example embodiments of the present invention, such as applying policy based routing, then destination based routing, may be implemented in a form of software, firmware, or hardware. If implemented in software, the software may be written in any language suitable to support operations consistent with those described herein. The software may be stored as computer readable instructions on any form of computer-readable medium, loaded by a processor, and executed by the processor or on multiple processors in a manner understood in the art. The processor(s) may be any form of general purpose or custom designed processor(s) suitable to perform operations illustrated by way of examples herein.
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
This application is a continuation of International Application No. PCT/US2007/013555, which designated the United States and was filed on Jun. 6, 2007. The entire teachings of the above application are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2007/013555 | Jun 2007 | US |
| Child | 12012208 | US |
