Congestion Control for RTP Media: A Comparison on Simulated Environment

Lei

Trans Emerging Tel Tech

et al. 2020

Self Cite

Even video telephony services have been pervasively applied, it is still a challenge to provide satisfactory quality of experience to users. Multipath transmission is a promising solution to improve video transmission quality by providing aggregated bandwidth. Due to varied traffic load, the default paths may fall into long lasting congestion. Sender has no choice but to reduce video bitrate to adapt such change, even in multipath transmission scenario. Insisting previous rate may lead the congestion in bottleneck deteriorate further. Deploying relay servers in current Internet infrastructure provides users with alternatives to bypass path failure and congestion. For such transmission scenario for video telephony service, an arising question is how to select paths dynamically to gain maximum profit. The path selection is mapped to the multi‐armed bandit problem. Tradeoff is made between exploration and exploitation to make decision under uncertain environment. The estimated bandwidth provided by congestion controller is used for decision‐making. Further, to make multiple flows share resource fairly and avoid congestion, an algorithm adapted from BBR is implemented for video telephony service. To maintain throughput stability and fairness, a smaller probe up gain value is used and the cycle length in bandwidth probe phase is randomized. To reduce delay, the inflight packets will be drained to match with bandwidth delay product in the probe down phase. The effectiveness of the proposed solution is verify on simulation platform.

Section: Related Workmentioning

confidence: 99%

An online learning based path selection for multipath real‐time video transmission in overlay network

Lei

Trans Emerging Tel Tech

et al. 2020

Self Cite

IEEE Open J. Commun. Soc.

“…Three algorithm were designed for RTP/RTCP over UDP as part of the WebRTC initiative: SCReAM [19], NADA [20], and GCC [21], [22]. SCReAM is based on LEDBAT, similar to its predecessor SCReAM has a low queue occupancy, but low channel utilization [23]. NADA uses a composite congestion signal, which consists of delay, loss, and explicit congestion notification markings.…”

Section: Background and Related Workmentioning

confidence: 99%

“…NADA uses a composite congestion signal, which consists of delay, loss, and explicit congestion notification markings. Having the highest channel utilization of the three algorithms, NADA suffers from the latecomer effect [23]. Similarly to SCReAM, GCC largely relies on one-way delay measurements.…”

Section: Background and Related Workmentioning

confidence: 99%

See 1 more Smart Citation

PIBES - A Competing-Flow-Aware Protocol for Real-Time Video Applications

Heimbach

Guo

Ngan

et al. 2020

With the recent explosive growth in online classes and virtual meetings, real-time video communication has quickly become an essential tool to everyone. Despite its widespread deployment, our investigation revealed that current protocols, ranging from industry standards such as WebRTC, to state-of-the-art research such as Salsify, often perform sub-optimally in the presence of competing flows sharing the same bottleneck. For example, WebRTC's throughput can degrade from 73% to a mere 8% of the available bandwidth when competing with just two TCP flows. We tackle this problem in this work by developing a novel PIPES protocol designed for real-time video applications in the presence of competing TCP traffic. PIPES employs a new inband bandwidth estimation method that can quickly and accurately measure the bottleneck link bandwidth even with competing flows. Moreover, PIPES can detect the absence or presence of competing flows which enables it to maximize video quality when there is no competing flow, and to maintain acceptable video quality while sharing bandwidth with competing flows. Experiments demonstrate that PIPES achieves throughput and delay comparable to the state-of-art protocols, but outperforms them significantly in the presence of competing TCP flows.

“…BBR algorithm is also implemented in WebRTC, but there is no report available on its performance in real network until now. In our previous work [36], performance comparison on GCC, NADA, SCReAM and WebRTC-BBR is conducted on ns3. Here, the performance of GCC, WebRTC-BBR and our optimized version is tested with link configuration in Case 1, 4, 7.…”

Section: Requirementioning

confidence: 99%

Congestion Control and Packet Scheduling for Multipath Real Time Video Streaming

et al. 2019

Self Cite

Real time video traffic has stringent delay requirement and is bandwidth demanding when streaming over the internet. Single path transmission may provide unsatisfactory picture quality to users due to packet loss, jitter, and low bandwidth. Multipath transmission is another option to achieve better service by aggregating bandwidth and exploiting path diversity. As utility maximization theory shows, to achieve better satisfaction is to provide higher throughput and lower frame delivery delay for real time video traffic. The congestion control is responsible to probe maximum available bandwidth and packet scheduling is to take advantages of path diversity, which are two key research points in multipath context and are also the main concern in this paper. Given the BBR congestion control algorithm causes high-packet loss rate and large transmission delay when BBR flows competing for bandwidth resource, a delay response BBR (Delay-BBR) algorithm is proposed for real time video transmission. The main idea is that the sender will actively reduce the rate to let intermediate routers drain the excess occupied buffer once round trip delay signal exceeds a certain threshold. The results show that the delay-BBR can achieve lower transmission delay and lower packet loss rate when compared with QUIC-BBR and WebRTC-BBR. The rate stable feature makes delay-BBR appropriate for real time video transmission. Moreover, a packet scheduling algorithm works in coordination with the rate control algorithm achieves lower frame delivery delay further compared with the benchmark algorithms.INDEX TERMS Multipath transmission, load distribution, real time video traffic, congestion control.