--- 1/draft-ietf-rmcat-wireless-tests-01.txt 2016-05-07 22:15:55.953319776 -0700 +++ 2/draft-ietf-rmcat-wireless-tests-02.txt 2016-05-07 22:15:55.993320774 -0700 @@ -1,24 +1,24 @@ Network Working Group Z. Sarker Internet-Draft I. Johansson Intended status: Informational Ericsson AB -Expires: May 8, 2016 X. Zhu +Expires: November 8, 2016 X. Zhu J. Fu W. Tan M. Ramalho Cisco Systems - November 5, 2015 + May 7, 2016 Evaluation Test Cases for Interactive Real-Time Media over Wireless Networks - draft-ietf-rmcat-wireless-tests-01 + draft-ietf-rmcat-wireless-tests-02 Abstract It is evident that to ensure seamless and robust user experience across all type of access networks multimedia communication suits should adapt to the changing network conditions. There is an ongoing effort in IETF RMCAT working group to standardize rate adaptive algorithm(s) to be used in the real-time interactive communication. In this document test cases are described to evaluate the performances of the proposed endpoint adaptation solutions in LTE @@ -34,25 +34,25 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on May 8, 2016. + This Internet-Draft will expire on November 8, 2016. Copyright Notice - Copyright (c) 2015 IETF Trust and the persons identified as the + Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as @@ -69,35 +69,35 @@ 3.2. Bad Radio Coverage . . . . . . . . . . . . . . . . . . . 8 3.2.1. Network connection . . . . . . . . . . . . . . . . . 9 3.2.2. Simulation Setup . . . . . . . . . . . . . . . . . . 9 3.3. Desired Evaluation Metrics for cellular test cases . . . 10 4. Wi-Fi Networks Specific Test Cases . . . . . . . . . . . . . 10 4.1. Bottleneck in Wired Network . . . . . . . . . . . . . . . 12 4.1.1. Network topology . . . . . . . . . . . . . . . . . . 12 4.1.2. Test setup . . . . . . . . . . . . . . . . . . . . . 13 4.1.3. Typical test scenarios . . . . . . . . . . . . . . . 14 4.1.4. Expected behavior . . . . . . . . . . . . . . . . . . 14 - 4.2. Bottleneck in Wi-Fi Network . . . . . . . . . . . . . . . 14 + 4.2. Bottleneck in Wi-Fi Network . . . . . . . . . . . . . . . 15 4.2.1. Network topology . . . . . . . . . . . . . . . . . . 15 4.2.2. Test setup . . . . . . . . . . . . . . . . . . . . . 15 4.2.3. Typical test scenarios . . . . . . . . . . . . . . . 16 4.2.4. Expected behavior . . . . . . . . . . . . . . . . . . 17 - 4.3. Potential Potential Test Cases . . . . . . . . . . . . . 17 - 4.3.1. EDCA/WMM usage . . . . . . . . . . . . . . . . . . . 17 - 4.3.2. Legacy 802.11b Effects . . . . . . . . . . . . . . . 17 + 4.3. Potential Potential Test Cases . . . . . . . . . . . . . 18 + 4.3.1. EDCA/WMM usage . . . . . . . . . . . . . . . . . . . 18 + 4.3.2. Legacy 802.11b Effects . . . . . . . . . . . . . . . 18 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 18 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 8. Security Considerations . . . . . . . . . . . . . . . . . . . 18 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 - 9.1. Normative References . . . . . . . . . . . . . . . . . . 18 - 9.2. Informative References . . . . . . . . . . . . . . . . . 19 + 9.1. Normative References . . . . . . . . . . . . . . . . . . 19 + 9.2. Informative References . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 1. Introduction Wireless networks (both cellular and Wi-Fi [IEEE802.11] local area network) are an integral part of the Internet. Mobile devices connected to the wireless networks produces huge amount of media traffic in the Internet. They covers the scenarios of having a video call in the bus to media consumption sitting on a couch in a living @@ -443,82 +443,79 @@ 4. Wi-Fi Networks Specific Test Cases Given the prevalence of Internet access links over Wi-Fi, it is important to evaluate candidate RMCAT congestion control solutions over Wi-Fi test cases. Such evaluations should also highlight the inherent different characteristics of Wi-Fi networks in contrast to Wired networks: o The wireless radio channel is subject to interference from nearby - transmitters, multi-path fading, and shadowing, causing + transmitters, multipath fading, and shadowing, causing fluctuations in link throughput and sometimes an error-prone communication environment o Available network bandwidth is not only shared over the air - between concurrent users, but also between uplink and downlink + between cocurrent users, but also between uplink and downlink traffic due to the half duplex nature of wireless transmission medium. - o Packet transmissions over Wi-Fi are susceptible to contentions and + o Packet transmessions over Wi-Fi are susceptible to contentions and collisions over the air. Consequently, traffic load beyond a certain utilization level over a Wi-Fi network can introduce frequent collisions and significant network overhead. This, in turn, leads to excessive delay, retransmission, loss and lower effective bandwidth for applications. o The IEEE 802.11 standard (i.e., Wi-Fi) supports multi-rate transmission capabilities by dynamically choosing the most - appropriate modulation scheme for a given received signal + appropriate modulation scheme for a given received singal strength. A different choice of Physical-layer rate will lead to different application-layer throughput. - o Presence of legacy 802.11b networks can significantly slow down - the rest of a modern Wi-Fi Network, since it takes longer to + o Presence of legancy 802.11b networks can significantly slow down + the the rest of a modern Wi-Fi Network, since it takes longer to transmit the same packet over a slower link than over a faster link. [Editor's note: maybe include a reference here instead.] o Handover from one Wi-Fi Access Point (AP) to another may cause packet delay and loss. o IEEE 802.11e defined EDCA/WMM (Enhanced DCF Channel Access/Wi-Fi Multi-Media) to give voice and video streams higher priority over pure data applications (e.g., file transfers). As we can see here, presence of Wi-Fi network in different network topologies and traffic arrival can exert different impact on the network performance in terms of video transport rate, packet loss and delay that, in turn, effect end-to-end real-time multimedia congestion control. Throughout this draft, unless otherwise mentioned, test cases are - described using 802.11g due to its wide availability in network - simulation platform. In practice, however, statistics collected from - enterprise networks show that the dominant physical modes are 802.11n - and 802.11ac, accounting for 73.6% and 22.5% of enterprise network - users, respectively. Whenever possible, it is recommended to extend - some of the experiments to 802.11n and 802.11ac, so as to reflect a - more modern Wi-Fi network setting. + described using 802.11n due to its wide availability in real-world + networks. Statistics collected from enterprise Wi-Fi networks show + that the dominant physical modes are 802.11n and 802.11ac, accounting + for 73.6% and 22.5% of enterprise network users, respectively. Since Wi-Fi network normally connects to a wired infrastructure, either the wired network or the Wi-Fi network could be the bottleneck. In the following section, we describe basic test cases for both scenarios separately. The same set of performance metrics as in [I-D.ietf-rmcat-eval-test]) should be collected for each test case. While all test cases described below can be carried out using simulations, e.g. based on [ns-2] or [ns-3], it is also recommended to perform testbed-based evaluations using Wi-Fi access points and endpoints running up-to-date IEEE 802.11 protocols. [Editor's Note: need to add some more discussions on the pros and cons of simulation- - based vs. testbed-based evaluations. It will be good to provide + based vs. testbed-based evaluations. Will be good to provide recommended testbed configurations. ] 4.1. Bottleneck in Wired Network The test scenarios below are intended to mimic the set up of video conferencing over Wi-Fi connections from the home. Typically, the Wi-Fi home network is not congested and the bottleneck is present over the wired home access link. Although it is expected that test evaluation results from this section are similar to those from test cases defined for wired networks (see [I-D.ietf-rmcat-eval-test]), it @@ -561,23 +558,23 @@ 4.1.2. Test setup o Test duration: 120s o Wi-Fi network characteristics: * Radio propagation model: Log-distance path loss propagation model [NS3WiFi] - * PHY- and MAC-layer configuration: IEEE 802.11g + * PHY- and MAC-layer configuration: IEEE 802.11n - * PHY-layer link rate: 54 Mbps + * MCS Index at 11: 16-QAM 1/2, Raw Data Rate@52Mbps o Wired path characteristics: * Path capacity: 1Mbps * One-Way propagation delay: 50ms. * Maximum end-to-end jitter: 30ms * Bottleneck queue type: Drop tail. @@ -597,59 +594,67 @@ + Number of media sources (N): See Section 4.1.3 + Media timeline: - Start time: 0s. - End time: 119s. * Competing traffic: - + Type of sources: long-lived TCP + + Type of sources: long-lived TCP or CBR over UDP + Traffic direction: See Section 4.1.3 + Number of sources (M): See Section 4.1.3 - + Congestion control: Default TCP congestion control [TBD] - - + Traffic timeline: - - - Start time: 0s + + Congestion control: Default TCP congestion control [TBD] or + CBR over UDP - - End time: 119s + + Traffic timeline: See Section 4.1.3 4.1.3. Typical test scenarios o Single uplink RMCAT flow: N=1 with uplink direction and M=0. o One pair of bi-directional RMCAT flows: N=2 (with one uplink flow and one downlink flow); M=0. + o One pair of bi-directional RMCAT flows, one on-off CBR over UDP + flow on uplink : N=2 (with one uplink flow and one downlink flow); + M=1 (uplink). CBR flow on time at 0s-60s, off time at 60s-119s + + o One pair of bi-directional RMCAT flows, one off-on CBR over UDP + flow on uplink : N=2 (with one uplink flow and one downlink flow); + M=1 (uplink). UDP off time: 0s-60s, on time: 60s-119s + o One RMCAT flow competing against one long-live TCP flow over - uplink: N=1 (uplink) and M = 1(uplink). + uplink: N=1 (uplink) and M = 1(uplink), TCP start time: 0s, end + time: 119s. 4.1.4. Expected behavior o Single uplink RMCAT flow: the candidate algorithm is expected to detect the path capacity constraint, converges to bottleneck link's capacity and adapt the flow to avoid unwanted oscillation when the sending bit rate is approaching the bottleneck link's - capacity. No excessive rate oscillations. + capacity. No excessivie rate oscillations. o Bi-directional RMCAT flows: It is expected that the candidate algorithms is able to converge to the bottleneck capacity of the - wired path on both directions despite of the presence of - measurement noise over the Wi-Fi connection. + wired path on both directions despite presense of measurment noise + over the Wi-Fi connection. In the presence of background TCP or + CBR over UDP traffic, the rate of RMCAT flows should adapt in a + timely manner to changes in the available bottleneck bandwidth. o One RMCAT flow competing with long-live TCP flow over uplink: the candidate algorithm should be able to avoid congestion collapse, - and stabilize at a fair share of the bottleneck capacity over the + and stablize at a fair share of the bottleneck capacity over the wired path. 4.2. Bottleneck in Wi-Fi Network These test cases assume that the wired portion along the media path are well-provisioned. The bottleneck is in the Wi-Fi network over wireless. This is to mimic the enterprise/coffee-house scenarios. 4.2.1. Network topology @@ -657,23 +662,23 @@ 4.2.2. Test setup o Test duration: 120s o Wi-Fi network characteristics: * Radio propagation model: Log-distance path loss propagation model [NS3WiFi] - * PHY- and MAC-layer configuration: IEEE 802.11g + * PHY- and MAC-layer configuration: IEEE 802.11n - * PHY-layer link rate: 54 Mbps + * MCS Index at 11: 16-QAM 1/2, Raw Data Rate at 52Mbps o Wired path characteristics: * Path capacity: 100Mbps * One-Way propagation delay: 50ms. * Maximum end-to-end jitter: 30ms * Bottleneck queue type: Drop tail. @@ -693,115 +698,129 @@ + Number of media sources (N): See Section 4.2.3 + Media timeline: - Start time: 0s. - End time: 119s. * Competing traffic: - + Type of sources: long-lived TCP + + Type of sources: long-lived TCP or CBR over UDP + Number of sources (M): See Section 4.2.3 + Traffic direction: See Section 4.2.3 - + Congestion control: Default TCP congestion control [TBD] - - + Traffic timeline: - - - Start time: 0s + + Congestion control: Default TCP congestion control [TBD] or + CBR over UDP - - End time: 119s + + Traffic timeline: See Section 4.2.3 4.2.3. Typical test scenarios This sections describes a few specific test scenarios that are deemed as important for understanding behavior of a RMCAT candidate solution over a Wi-Fi network. o Multiple RMCAT Flows Sharing the Wireless Downlink: N=16 (all downlink); M = 0; This test case is for studying the impact of contention on competing RMCAT flows. Specifications for IEEE - 802.11g with a physical-layer transmission rate of 54 Mbps is - chosen. Note that retransmission and MAC-layer headers and - control packets may be sent at a lower link speed. The total - application-layer throughput (reasonable distance, low - interference and small number of contention stations) for 802.11g - is around 20 Mbps. Consequently, a total of N=16 RMCAT flows are - needed for saturating the wireless interface in this experiment. - Evaluation of a given candidate solution should focus on whether - downlink RMCAT flows can stabilize at a fair share of bandwidth. + 802.11n, MCS Index at 11: 16-QAM 1/2, Raw Data Rate at 52Mbps is + chosen. Note that retransmissions, MAC-layer headers, and control + packets may be sent at a lower link speed. The total application- + layer throughput (reasonable distance, low interference and small + number of contention stations) for 802.11n is around 20 Mbps. + Consequently, a total of N=16 RMCAT flows are needed for + saturating the wireless interface in this experiment. Evaluation + of a given candidate solution should focus on whether downlink + RMCAT flows can stablize at a fair share of bandwidth. o Multiple RMCAT Flows Sharing the Wireless Uplink: N = 16 (all downlink); M = 0; When multiple clients attempt to transmit video packets uplink over the wireless interface, they introduce more frequent contentions and potentially collisions. Per-flow throughput is expected to be lower than that in the previous downlink-only scenario. Evaluation of a given candidate solution - should focus on whether uplink flows can stabilize at a fair share + should focus on whether uplink flows can stablize at a fair share of bandwidth. o Multiple Bi-directional RMCAT Flows: N = 16 (8 uplink and 8 - downlink); M = 0. The goal of this test is to evaluate + downlink); M = 0. the goal of this test is to evaluate performance of the candidate solution in terms of bandwidth fairness between uplink and downlink flow. + o Multiple Bi-directional RMCAT Flows with on-off CBR traffic: N = + 16 (8 uplink and 8 downlink); M = 5(uplink). The goal of this + test is to evaluate upgrading performance of the candidate + solution in terms of available bandwidth changes caused by the CBR + uplink flow over UDP. CBR over UDP background flows have on time + 0s-60s, and off time 60s-119s + + o Multiple Bi-directional RMCAT Flows with off-on CBR traffic: N = + 16 (8 uplink and 8 downlink); M = 5(uplink). The goal of this + test is to evaluate upgrading performance of the candidate + solution in terms of available bandwidth changes caused by the CBR + uplink flow over UDP. CBR over UDP background flows have off time + 0s-60s, and on time 60s-119s. + o Multiple RMCAT flows in the presence of background TCP traffic: the goal of this test is to evaluate how RMCAT flows compete against TCP over a congested Wi-Fi network for a given candidate - solution. [Editor's Note: more detailed description will be added - in the next version in terms of directoin/number of RMCAT and TCP - flows. ] + solution. TCP start time: 0s, end time: 119s. [Editor's Note: + more detailed description will be added in the next version in + terms of directoin/number of RMCAT and TCP flows. ] o Varying number of RMCAT flows: the goal of this test is to evaluate how a candidate RMCAT solution responds to varying traffic load/demand over a congested Wi-Fi network. [Editor's Note: more detailed description will be added in the next version in terms of arrival/departure pattern of the flows.] 4.2.4. Expected behavior o Multiple downlink RMCAT flows: All RMCAT flows should get fair share of the bandwidth. Overall bandwidth usage should be no less than same case with TCP flows (using TCP as performance benchmark). The delay and loss should be within acceptable range for real-time multimedia flow. o Multiple uplink RMCAT flows: overall bandwidth usage shared by all RMCAT flows should be no less than those shared by the same number of TCP flows (i.e., benchmark performance using TCP flows). - o Multiple bi-directional RMCAT flows: overall bandwidth usage - shared by all RMCAT flows should be no less than those shared by - the same number of TCP flows (i.e., benchmark performance using - TCP flows). All downlink RMCAT flows are expected to obtain - similar bandwidth with respect to each other. + o Multiple bi-directional RMCAT flows with CBR over UDP traffic: + RMCAT flows should adapt to the changes in available bandwidth. + + o Multiple bi-directional RMCAT flows with TCP traffic: overall + bandwidth usage shared by all RMCAT flows should be no less than + those shared by the same number of TCP flows (i.e., benchmark + performance using TCP flows). All downlink RMCAT flows are + expected to obtain similar bandwidth with respect to each other. 4.3. Potential Potential Test Cases 4.3.1. EDCA/WMM usage EDCA/WMM is prioritized QoS with four traffic classes (or Access Categories) with differing priorities. RMCAT flow should have better performance (lower delay, less loss) with EDCA/WMM enabled when competing against non-interactive background traffic (e.g., file transfers). When most of the traffic over Wi-Fi is dominated by media, however, turning on WMM may actually degrade performance. This is a topic worthy of further investigation. 4.3.2. Legacy 802.11b Effects When there is 802.11b devices connected to modern 802.11 network, it may affect the performance of the whole network. Additional test - cases can be added to evaluate the affects of legacy devices on the + cases can be added to evaluate the affects of legancy devices on the performance of RMCAT congestion control algorithm. 5. Conclusion This document defines a collection of test cases that are considered important for cellular and Wi-Fi networks. Moreover, this document also provides a framework for defining additional test cases over wireless cellular/Wi-Fi networks. 6. Acknowledgements @@ -838,23 +856,23 @@ . [HO-UMTS-3GPP] TS 25.331, 3GPP., "Radio Resource Control (RRC); Protocol specification", December 2011, . [I-D.ietf-rmcat-eval-criteria] - Singh, V. and J. Ott, "Evaluating Congestion Control for - Interactive Real-time Media", draft-ietf-rmcat-eval- - criteria-04 (work in progress), October 2015. + Varun, V., Ott, J., and S. Holmer, "Evaluating Congestion + Control for Interactive Real-time Media", draft-ietf- + rmcat-eval-criteria-05 (work in progress), March 2016. [NS3WiFi] "Wi-Fi Channel Model in NS3 Simulator", . [QoS-3GPP] TS 23.203, 3GPP., "Policy and charging control architecture", June 2011, . @@ -864,23 +882,23 @@ . 9.2. Informative References [I-D.ietf-rmcat-cc-requirements] Jesup, R. and Z. Sarker, "Congestion Control Requirements for Interactive Real-Time Media", draft-ietf-rmcat-cc- requirements-09 (work in progress), December 2014. [I-D.ietf-rmcat-eval-test] - Sarker, Z., Singh, V., Zhu, X., and M. Ramalho, "Test + Sarker, Z., Varun, V., Zhu, X., and M. Ramalho, "Test Cases for Evaluating RMCAT Proposals", draft-ietf-rmcat- - eval-test-02 (work in progress), September 2015. + eval-test-03 (work in progress), March 2016. [IEEE802.11] "Standard for Information technology--Telecommunications and information exchange between systems Local and metropolitan area networks--Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications", 2012. [LTE-simulator] "NS-3, A discrete-Event Network Simulator",