E2E Transport Network Solution

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Ericsson Demonstrates Endto End Mobile Transport Solutions

Advisory Report

March 15, 2011

Issue

Mobile operators are being challenged to deliver on new high value services that stress their current mobile network infrastructures by requiring nearly unlimited levels of bandwidth, fl exibility and to provide a high level of quality of experience; all the while lowering the price per bit which tends to limit service provider profi t margins. In addition to economic and technical challenges, operators face the threat of subscriber churn if they do not deliver on expected services in a timely manner.

Ericsson’s end-to-end network infrastructure products off er operators, both fi xed and mobile, a range of solutions that claim to address the most pressing issues as they continue their infrastructure investments. It is the “claims” portion of this proposition that the recent Ericsson mobile transport infrastructure demonstrations set out to prove. As part of this process, Ericsson and Current Analysis contracted Isocore to perform due diligence on the test plans proposed for a demonstration of Erics-son End-to-End mobile solution off ering. Isocore provided comments and ensured through witness-ing that the testing adhered to the fi nal test plans. However, Isocore did not lead an in-depth testing activity and analysis of results. In February 2011, representatives of Current Analysis and Isocore were given the opportunity to observe, fi rst hand, the fi ner points of delivering a multigenerational mobile network solution that addresses key pain points expressed by mobile operators as they sort through the myriad of options, architectures, and product/solution choices available to them in the marketplace.

Th e solution demonstrations were conducted in Ericsson’s Eurolab IP Networks facility located in Aachen Germany. High level tests were executed that proved that the company’s end to end mobile infrastructure solutions could deliver support for multiple generations of mobile traffi c, 2G, 3G and 4G/LTE, provide network synchronization, demonstrate the quality and service and resiliency of its microwave transport solution, and show the solutions delivered the expected quality of experience under simulated network anomalies. In all cases, the test scenarios observed by the Current Analysis team members delivered the expected results – demonstrating the validity of Ericsson’s claims to deliver pre-tested and proven solutions for mobile backhaul, IP RAN and mobile core segments of the network. Th e following sections of this report provide background regarding the requirements placed on infrastructure to meet expectations and describe the specifi c tests and observed results.

Current Perspective

The ChallengeMobile operators face multiple challenges to support basic and advanced mobile services, which are transitioning from predominately voice and limited data to a service mix which is trending toward

Glen HuntCurrent AnalysisPrincipal Analyst, Transport and Routing Infrastructure


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an unpredictable mix of video, high bandwidth data services, plus the continued need to sup-port existing 2G and 3G traffi c. Complicating the picture are demands from mobile users who want to pay less per bit, expect always-on operation, and demands for a high quality of experi-ence from their providers. Beyond cell site capacity issues which often gain center stage, the backhaul network has been and remains a well-known choke point in many networks. Operators evaluating backhaul solutions must also be cognizant of the interdependencies that RAN has with backhaul which includes how the multiple generations of traffi c are supported, native or emulated transport, network timing and synchronization, network delay and jitter, and last by not least, resiliency and recovery from network failures – either equipment of circuit induced. Although the challenges are many, when viewed as an end to end transport solution, operators have a framework to address their specifi c needs.

The TrendsMobile operators can try, and in some cases, skip the complexity of supporting legacy services, and will often fi nd the concept of building an all-IP infrastructure optimized to support 4G LTE services attractive. Th e all-IP model brings with it fewer “moving parts” and a true focus on delivering high bandwidth video and data services. However, reality quickly steps in and provides a level set – current services need to be supported, which brings the need to support traditional TDM and ATM-based support back into the mix. Mobile operators are also often forced to leverage existing infrastructure investments until they are fully depreciated or taken out of service. And, as hyped as 4G services appear in the media, the bulk of operator revenues come from exist-ing services and from the continued evolution based on technologies such as HSPA+ and EVDO, which address an immediate need to provide higher performance 3G data services. Th ere appears to be little doubt that the goal is to provide 4G services over an infrastructure that will represent a convergence of previous generations, with LTE service materializing beginning in earnest in the 2011, the industry appears to be in agreement.

The SolutionsGiven the complexity of delivering mobile services, operators are challenged to make investment decisions, but often lack the assurances from their suppliers that these investments will position them to best address the needs of a highly fl exible and unpredictable market place. Operators seeking solutions can take several approaches, they can follow the traditional route of selecting individual network components, such as cell site and aggregation routers, edge switches, mobile core, microwave, fi ber access, and a management system to provide the operation and service provisioning support to deliver, trouble shoot and monitor network performance.

An alternative approach where the operator leverages pre-integrated and pre-tested solutions appears to gaining momentum. Th e solutions approach can one more viable and one that many operators are pursuing to reduce risk, improve time to market, optimize cost, and to obtain op-erational systems capable of enabling them to off er fl exible high value services, and position their infrastructures to meet the current and future challenges. Vendors such as Ericsson have packaged a combination of mobile transport solutions that enables operators to proceed with a high level of certainty and leverage an end to end solution that addresses the challenges noted above. Depend-ing upon mobile operator preferences, they can leverage one of three solutions off ered by Ericsson – or combine them to provide an end to end mobile transport network. Th e three solutions separately include the Mobile Packet Backbone Network (MPBN), which provides a transport solution for 2G, 3G and LTE mobile core networks; the IP RAN, which provides infrastructure and connectivity of GSM, WCDMA and LTE radio networks; and the Mobile Backhaul (MBH), which provides the infrastructure to interconnect the IP RAN and core.

Benefi ts of a solutions approachPretested and integrated solutions for the entire mobile network infrastructure, or segments of the infrastructure, can pay signifi cant dividends for mobile operators in several areas, such as reduced

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Ericsson Demonstrates

End to End Mobile Transport Solutions

Transport and RoutingInfrastructure


Advisory Report

testing and validation time, interoperability among the various components of the soltuion, proven backup and resiliency mechnaizms with known performance, management and provi-sioning support to reduce OpEx, and a consistent implementation of traffi c prioritization and classifi cation techniques to address the quality of experience so important to the end user and in the case of M2M traffi c the application. As an industry, there have seen multiple demonstrations of multi-vendor interoperability, including, Ethernet centric platforms to deliver cost eff ective high bandwidth services, emulation services for TDM, rigorous timing and synchronization tests to prove fi eld readiness of technologies such as IEEE 1588 and Synchronous Ethernet, and a few attempts to demonstrate end to end OAM and network performance monitoring. Operators; however, are becoming a bit more concerned about the ability of devices to work in concert to meet their overall services needs, less about the individual device specifi cations, and the vendor’s unit-level testing of those devices. Signifi cant benefi ts can be realized by off ering operators a fully tested solution that provides the scalability and fl exibility to adapt to all forms of traffi c and service demands.

Mobile End to End Transport SolutionsCurrent Analysis participated in suite of end to end mobile transport demonstrations based on Ericsson’s mobile transport infrastructure solutions. Th e demonstrations were conducted in its Eurolab IP Networks facility located in Aachen Germany in February 2011. Th e Ericsson team extracted several high level test scenarios that went toward proving the value in leverag-ing Ericsson’s pre-tested solutions and to show the depth of their transport solutions. Testing included its optical, Ethernet and microwave products which together forms a complete network. Th e demonstrations selected, verifi ed the ability of the solutions to carry multiple generations of mobile traffi c, including LTE. And, on the more subtle side, the demonstrations proved that the solutions could provide end to end quality of services based on traffi c and subscriber profi les – a signifi cant challenge facing most operators as they seek acceptable ways to deliver premium as well as best eff ort services.

It is important to note that the demonstrations were not focused toward proving the functionality of each individual component or device in the transport network. Th e following test cases were executed for the Current Analysis participants, and fully addressed the challenges noted above. For each case, we have noted the results observed from running the respective tests scenarios. In addition to observing the results of the tests, we were able to participate in creating network anomalies – some as severe as disrupting equipment power to demonstrate complete node fail-over and recovery. Perhaps the dream of every tester is to fi nd a test scenario where a defect or un-explained behavior is detected, unfortunately, this did not occur in the testing, all of the test cases worked as designed and demonstrated advanced functionality based on a solid foundation.

Test EnvironmentTwo test profi les were used in the demonstrations, a baseline profi le to create an artifi cial network load on top of the traffi c created by the user applications, and to perform exact outage calcula-tions during resilience tests. For that purpose, bidirectional traffi c streams were injected into the network. A high load setup was also used for selected Quality of Service and load tests. Th e streams defi ned were used to put additional traffi c on selected hops of the network in order to cause high load conditions on selected links/interfaces to induce overload, forced traffi c manage-ment to curb best eff ort traffi c, and to show resiliency and recovery operations. Click here for access to the test plan including details regarding the specifi cs of the test setup such as equipment type, interfaces, and confi gurations.

2G/3G End to End IntegrationTh is test scenario was comprised of voice calls, internet access, video streaming, IPv6 transport, 2G and 3G mobile access. Th e initial tests required that separate 2G and 3G voice calls be placed over the test infrastructure, which leveraged a remote site (Linköping, Sweden). Th e test network

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http://www.currentanalysis.com/t/2011/testspec/


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was running the baseline traffi c profi le, and we where we were able to observe the video display-ing an HD movie, best eff ort internet traffi c and video monitors showing the local site and the remote sites for the voice connection. We observed that the voice quality was good for both calls by using the appropriate hand sets and the applications running did not show any distress such as pixilation or distortion as a result of activating the voice calls.

A 2G (GSM)/ 3G (UMTS) radio bearer, respectively, was used on both sides involving the Ericsson BTS, BSC, MSC-BC, M-MGw and HLR radio and core nodes. Th e signaling and voice transport for the radio access of MS1/UE1 (Aachen) is accomplished using the MINI-LINK, SEA and OMS systems which are part of the Ericsson Mobile Backhaul (MBH) network solution build up in Aachen. In the Core Network, the call is routed between two Primary Sites of MPBN located in Aachen. To reach the radio access of MS2/UE2 (Linköping), the call was routed through the Ericsson Data Network to the remote cell site in Linköping.

3G PS ConnectionTh is test was conducted using an Apple iPad to display a video using HTTP Progressive Down-load. A PC with 3G modem was connected to the test lab internal web server, which initiated pings continuously and downloads of large fi les using the ftp protocol. For each user device (UE), a 3G (HSPA) radio bearer was used involving the Ericsson RBS, RNC, SGSN-MME, GGSN-MPG, SAPC and HLR radio and core nodes. Th e signaling and data transport for the radio access of the UE was accomplished using the Ericsson Mobile Backhaul (MBH) network solution in Aachen. In the Core Network, the call was then routed between two Primary Sites of MPBN located in Aachen. Th e connection to the Internet and the local web server was provided by a Juniper SRX Firewall/NAT solution. Best eff ort quality of service was assigned to the established PDP contexts.

Th e baseline network profi le was again used and the connections for the iPhone and PC/3G modem were connected, the video stream on the iPad was noted to have good visible quality (quality as observed), the ftp downloads were continuously running and reported not errors. We were able to observe bandwidth utilization on the Spirent test center, utilization tracked per the applications being executed. Since both, ftp download and video stream were transferred with best eff ort service, the video stream suff ered from the high bandwidth demand of the ftp service unless the PC subscription is limited in bandwidth. Of signifi cance with this test, is the treatment of best eff ort traffi c, which is allowed to consume available bandwidth which is not allocated to premium level traffi c, but there can be confl icts within the best eff ort where one application can interfere with others causing a level of service distress. Th e test was repeated, and the video iPhone subscription was assigned as a premium 3G service. Th e results showed that the stream, this time did not experience any distress due to the best eff ort traffi c, indicating that the QoS mechanisms were indeed operational.

3G PS ConnectionA PC with 3G modem was connected to the test lab internal web server using the IPv6 protocol, as before the test initiates pings continuously and displays a web page.

Th e test verifi ed that a true IPv6 connection was established and the ping recorded the round trip time over the connection, of signifi cance was the observation that the round trip delay when compared to an IPv4 ping, were similar in time duration. It would have been somewhat expected that the process would have taken additional time due to the more extensive address lookup and browser processes.

LTE End to End IntegrationTh is test shows the integration of additional end to end use cases using LTE mobile access technology, such as Internet access and video streaming, into the test network. Th e testing verifi ed that LTE use cases are operational within the test network and shows that the network


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handles the quality of service and bandwidth requirements properly. Th e cases included www and ftp services and HDTV video streaming. An LTE client and a live TV session were demonstrated. Of particular importance was the ability to transport best eff ort traffi c without impacting the guaranteed traffi c, indicating that the network properly prioritized and managed traffi c fl ows.

Th e LTE client connects to the Ericsson Evolved Packet Core via LTE radio. Th e network con-fi guration was the same as in the previous test cases except that diff erent protocols and links were used and the Ericsson CPG provided the SGi interface towards Internet and intranet servers. Best eff ort quality of service was assigned to the established evolved packet system bearers. Th e test included pinging a node on the network, HTTP browsing and FTP downloads. In addition, the LTE client presented High Defi nition streaming videos from a local HTTP/streaming server or the Internet. Full LTE throughput is shown end to end.

Th e basic testing confi rmed that an LTE subscriber could be provisioned, the applicable con-nections were made and a continuous ping could be setup, further a large fi le was successfully downloaded using Filezilla. Using best eff ort traffi c classifi cation, a HD video was played, it was observed that best eff ort traffi c from the background traffi c could impact the perceived quality of the video. Another session was activated, this time with premium quality of service assigned, the results were similar to the 3G premium testing, where there the quality of experience was preserved and no degradation in the video steam was visible.

Network SynchronizationTh e test case verifi ed that network synchronization functions performed reliably when delay and jitter are varied or when the bandwidth is reduced temporarily on links that carry synchroniza-tion signaling. Th e base station was confi gured with two NTP (Network Time Protocol) sources, when one of the sources was impaired, the base station switched to the alternative source. Th e test was repeated using a PTP (Precision Time Protocol) source, and when the primary source was impaired, the Site Integration Unit (SIU), which has a high stable oscillator (HS-OCXO), provided an accurate frequency that can be used as a timing source for base station (RBS) synchronization functionality (according to Ericsson- for several months), the eNodeB remained synchronized during this test.(Th e test participants did not observe the test for months, but were assured that the high precision clocking in the SIU would indeed function as noted).

Transport Microwave and OpticalMultiple transport tests were conducted using the MINI-LINK microwave and the OMS 1410 optical platforms. With the unquestionable trends toward adding capacity and resiliency to the mobile infrastructure, both solutions are needed to address these requirements. Th e microwave solutions provide the fi rst mile backhaul to service the increasing demands from the cell site; the optical solutions provide the same service when fi ber connections are available. Of signifi cance, is the ability of each platform to provide rigorous and consistent traffi c management. Th e trans-port tests noted below, and the QoE section that follows, rely heavily on these QoS and traffi c management mechanisms found in the two products. Common to both microwave and optical platforms is the ability to transport TDM and packet traffi c in their native format, the fi rst test executed demonstrated this capability on each platform, and we noted that both streams were forwarded without any frame loss.

Transport MicrowaveTh e microwave test scenarios demonstrated the reliability and quality of service capabilities of the MINI-LINK TN transport solution, and leveraged technologies such as adaptive modula-tion, queuing and radio link bonding to deliver quality services under impaired link conditions. Ericsson’s radio link bonding technique was shown, which when confi gured in a 2+0 confi gura-tion delivered a 100% increase in link performance, increased performance is critical to keeping up with bandwidth and subscriber growth. Since microwave transport represents a signifi cant


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alternative to fi ber, it is imperative that the system deliver high capacity performance, degrades gracefully during network impairments (such as weather related conditions), and can transport packet or TDM traffi c in their native formats. Th e microwave transport tests functioned as expected, and the test scenarios simulated each of the expected traffi c/weather conditions that would experienced in an actual network deployment.

Various tests were run to verify that radio link bonding provided the expected 100% increase in the Ethernet (packet) traffi c capacity, while maintaining 1+1 subnet circuit protection for the E1 (TDM) traffi c fl ows. Also demonstrated was the capability to support an increased level of best eff ort packet traffi c as well as the bandwidth management functions necessary to reduce the bandwidth allocated to the best eff ort fl ow when available bandwidth was reduced – showing that the TDM traffi c was unaff ected and the guaranteed traffi c was protected. Since microwave systems are impacted by weather conditions, another important verifi cation was performed that demonstrated the ability of the MINI-LINK, via its adaptive modulation, to show when absolute bandwidth is reduce that only low priority streams are aff ected. We observed this test in the simulated environment, where the test team increased the attenuation of the signal to reach the modulation switch thresholds, and forced the adaptive modulation functionality to take eff ect.

Th e fi nal transport test exercised the operation of the MINI-LINK’s queuing functionality, specifi cally the “weighted fair queuing”, which off ers a more fl exible way to schedule on an egress port and prevents starvation of traffi c class queues. WFQ can be used together with the Strict Priority scheme to achieve the desire traffi c profi les. Th e test was executed using strict priority queuing, which resulted in the loose of certain traffi c fl ows when an overload condition was reached, in some cases that is the desired result; however, the test was rerun with the system confi gured with WFQ turn on, and each queue given a percentage of available bandwidth, the results were much diff erent. Instead of dropping data, the queues were services according to their allocations, enabling all traffi c to be serviced. Given the intricacy of this queuing test, please see the detailed test plan for greater details.

End user Quality of Experience (QoE)Th is set of tests show that the end user’s QoE is not severely aff ected when the MBH and MPBN solutions are confronted with major disturbances, such as overload, link and node failures and other anomolies. Th e tests involve technologies such as Ring Protection and queuing as well as VRRP, OSPF, BGP and LDP protocols. One aspect of the QoE demonstration was to demon-strate that the network handles the quality of service and bandwidth requirements of the diff erent use cases in the best possible way when the underlying transmission network is forced to perform under degraded conditions (packet loss, latency and jitter). Multiple network disturbances were injected by the team including: removing a confi gured link, and monitoring the time required to switch over to a backup path; recover from a fully powered down node; and the insertion of network glitches such as traffi c overload to force policing based on traffi c class and priority. Th e tests produced the expected results and leveraged the combination of all three of Ericsson’s mobile infrastructure solutions to deliver an end to end solution. Th e signifi cant diff erence between these QoE tests and our previous testing, relates to the combination of all components that comprise the end to end mobile transport network, including the SmartEdge routers, Ethernet switches and the OMS 1410 optical transport systems that provide connectivity and mobile core process-ing. As with the other scenarios we observed, the network functioned as expected.

Th e QoE test cases verifi ed that major disturbances in the backbone and transport network com-prised of the OMS and MPBN solutions do not create severe impacts on the end-to-end services. It was noted that temporary (induced) degradation of the Quality of Experience was avoided. Th e test also shows that the network handles the quality of service and bandwidth requirements of the diff erent use cases properly when the underlying transmission network is forced to oper-ate without certain resources Th e backbone and transport network solution complies to these expectations by means of a fully redundant network design with fast fail-over capabilities and a

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well designed assignment of quality of service classes and their mapping to priority and weighted queues in the infrastructure equipment.

During this section of the demonstration, we observed and in some cases actually caused network faults to demonstrate QoE. We began by creating a link failure, by unplugging an MPLS core link confi gured between two SmartEdge routers performing the mobile core functions. We noted that the monitoring system identifi ed the failed link which caused the backbone routing process to re-route the traffi c onto other predetermined paths, within 1 second. Th e link failure was then reversed, and we observed that the pre-failure routes were reestablished. We were able to note that the test traffi c, which was continuously injected in the baseline profi le, was analyzed to determine the time to restore the link was well within the expected sub-second range. Multiple types of link failures we created to demonstrate the networks ability to switchover to alternative paths, restore to pre-failure states and continue to carry traffi c with little or no impact on the end user QoE.

Given the resiliency characteristics of the optical network, several tests were conducted to force switchovers within the OMS optical rings. With voice calls active across the network, several link failures were induced. Th e switchover time observed were within 50ms; no voice calls were dropped, and the failures did not cause any noticeable glitches in the voice quality of the calls in progress – as experienced via a mobile handset Th e eNodeB synch status was observed as remaining in LOCKED mode. Several tests were conducted which required a full shutdown of the OMS, these tests showed minimal disruption to the traffi c fl ows.

Perhaps the most impressive QoE test involved demonstrating how the network performed when an entire node failure occurred. Th e previous tests dealt with single link failures throughout the network, but this test forced the failure of a complete SmartEdge 1200 backbone router. Th e af-fected traffi c was re-routed onto the other SE1200 in under two seconds. Th e average delay noted on the IxN2X test traffi c increased after failure due, to additional hop in the traffi c’s path, but the impact on the end-to-end traffi c was negligible. Th e process was then reversed, the node was powered on, and after all the routing protocols were restarted, the system reverted to its pre-fail-ure state. Th e same scenario was conducted between the redundant SmartEdge 800 nodes service as the interface between the core and the mobile backhaul portion of the network.

Recommended Actions

Recommended Vendor Actions• Ericsson should continue to promote its end to end solutions, which can help mobile opera-tors derived signifi cant benefi ts in terms of time to market, establishing a fl exible and extensible architecture, and reducing the overall operational costs associated with delivering mobile services. Using the end to end message as an umbrella helps operators focus on delivering services over a proven architecture.

• Ericsson should also promote the ability of its three mobile solutions to work together in an all Ericsson network as well as the ability for the any one of the three solutions to work indepen-dently in a multi-vendor network. Mobile operators seeking to second source their networks will fi nd that they can leverage their solutions from the vendor of choice and still realize the benefi ts of having a pre-tested network sub-segment (such as the MBH, MPBN or the IP RAN).

• Ericsson should provide network operators with all requisite technical documentation and test results it has generated in the normal course of testing their solutions off ers. Increased informa-tion along these lines could help Ericsson generate additional interest in its solutions from operators early in evaluation and procurement process and help to reduce the time the operators spends in testing the infrastructure. By accepting a baseline set of functionality and performance, operators are then free to focus on service provisioning and aspects of their service delivery that


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enable them of off er diff erentiated services.

• Ericsson should continue to leverage its professional services capabilities as part of its value to operators. Although the three solutions come verifi ed and pre-tested, operators will seldom have the exact topology and confi guration as provided by Ericsson. With the inclusion of professional services, operators can easily customize the network to meet their specifi c requirements. Further, given a well defi ned architecture and implementation plan, operators will be capable of incremen-tally expanding their infrastructures as traffi c demand changes and as new services are turned up.

• Ericsson should continue to promote its mobile transport infrastructure as meeting the needs of emerging LTE services, but stress that it does so not at the expense of supporting legacy services. Equally important is the converse, where an operator needs to support current services but wants to add support for LTE services in the future (the future now being 2011 – 2014). Th e ability to support multiple generations of mobile traffi c and scale to meet continue growth demands, dem-onstrates the depth of experience and fi eld proven knowledge the Ericsson brings to the problem.

Recommended Buyer Actions• Mobile operators should evaluate Ericsson as a full service vendor and strategic partner who is capable of providing end to end solutions that are backed up by well know products and services. Operators should press Ericsson for assurances that its products and platforms will continue to be tested and integrated into deliverable solutions as a way to reduce time to market and help them rapidly scale their networks to meet growing bandwidth and service awareness.

• Mobile operators should request to receive all requisite technical documentation and test results during the initial evaluation exercises. Th is would enable operators to by-pass much of the unit and system level testing and validation (performed by the vendor), enabling them to focus on providing service diff erentiation and quality of experience.

• Mobile operators looking to upgrade their single generation mobile core network should look closely at Ericsson’s Mobile Packet Backbone Network (MPBN), which provides a transport solution for 2G, 3G and LTE mobile core networks.

• Mobile operators looking to upgrade their mobile backhaul infrastructures should look closely at Ericsson’s Mobile Backhaul (MBH), which provides the infrastructure to interconnect the MBH and IP Ran. Operators should make sure that their backhaul networks do not become the choke point when providing new high bandwidth services. Operators must also make sure that the backhaul network can deliver the level of QoS and bandwidth management needed to support the uncertainty of rapidly evolving packet based traffi c.

• Mobile operators looking to upgrade their mobile transport infrastructures should look closely at Ericsson’s the IP RAN, which provides infrastructure and connectivity of GSM, WCDMA and LTE radio networks.

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Click the following link for access to the test plan including details regarding the specifi cs of the test setup such as equipment type, interfaces, and confi gurations.http://www.currentanalysis.com/t/2011/testspec/

E2E Transport Network Solution

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Transcript of E2E Transport Network Solution