Delay Impact of Bursty Cross Traffic in Combined Input and Output Queued Switches Using Virtual Input Queueing Under Diverse Network and Traffic Conditions
2026· IEEE Open Journal of the Communications Society· Vol 7, pp. 10214-10228· 0 citations· 55 references
TL;DR
Simulation results show that the CIOQ switch with VIQs effectively isolates critical flow from the impact of bursty flow originating from other input ports, thereby mitigating delay degradation caused by cross-port interference under the examined traffic conditions.
Abstract
The rapid advancement of digital transformation (DX) requires networks to concurrently support diverse traffic types on a shared infrastructure. Next-generation infrastructures, such as the innovative optical and wireless network (IOWN) and high-speed data centers, require the coexistence of flows with disparate requirements. Here, low-delay critical communications (e.g., real-time control) must function alongside high-volume non-critical communications (e.g., background file transfers). While traffic shaping can effectively suppress the burstiness of critical flows, concurrent non-critical flows often exhibit significant temporal burstiness. In basic combined input and output queued (CIOQ) switches, such bursty flows can monopolize output FIFO buffers, causing significant delay degradation for critical flows. To mitigate this interference, this paper investigates a virtual input queue (VIQ) scheme, which provides logical isolation at the output stage. We evaluate its performance across diverse conditions via discrete-time simulations. Simulation results show that the CIOQ switch with VIQs effectively isolates critical flow from the impact of bursty flow originating from other input ports, thereby mitigating delay degradation caused by cross-port interference under the examined traffic conditions. They also reveal how the burstiness of non-critical flows, the number of switch ports, arrival rates, and traffic uniformity influence the performance.
Bufferbloat has become a severe degradation to performance in contemporary IP networks, especially to low-latency Internet traffic that has strong delay and jitter requirements. Over buffering in network equipments which initially is supposed to eliminate the loss of packets and enhance the throughput, tend to create continuously long queues, and consequently cause swelling end-to end latency and subpar Quality-of-Experience (QoE). In this paper, the author examines the effects of bufferbloat on the application performance of cars relying on latency sensitive applications: Voice over IP (VoIP), online gaming, augmented and virtual reality (AR/VR) and real-time teleoperation. We initial discuss the underlying causes of bufferbloat, namely buffer size, conservative drop policy and the interaction between transport layer congestion control and transport layer congestion control. The paper subsequently defines low-latency traffic needs and points out that it is susceptible to queueing and jitter delays, as well as bursty packet loss. A controlled testbed based on access-network conditions with mixed traffic loads is used as an experimental evaluation. The drop-tail buffering is contrasted with Active Queue Management (AQM) methods to measure their impacts in terms of latency, throughput, fairness and coexistence with the legacy TCP flows. Findings show that uncontrolled buffers have a significant negative effect on the performance of low-latency traffic in congestion but that AQM mechanisms can be carefully tuned to achieve a substantial reduction in queueing delay without seriously impacting throughput. Lastly, the paper explains the open issues regarding bufferbloat in wireless networks and mobile networks, new applications based on ultra-low-latency, and the correct measurement and detection of operational networks. The results offer empirical evidence to the network designers and researchers whose goal is to develop latency-sensitive Internet infrastructures.
Dr. Sudhanshu Gonge¹, Dr Kalyani Kadam², Dr. Deepak Yashwant et al.· Journal of Intelligent Decis...· 0 citations
In data centers, large-scale many-to-one traffic can rapidly exhaust switch buffers and trigger priority-based flow control (PFC) pause, resulting in increased flow completion time (FCT) for uncongested flows. To address this issue, we propose an innovative switch-side fast and accurate flow control (FAFC) scheme. By differentially allocating pause time for each port during congestion, FAFC can minimize the performance loss for uncongested flows. Furthermore, FAFC is also coupled with an effective queue length prediction algorithm to enable proactive and reliable estimation of the congestion level. Extensive system-level simulations demonstrate that FAFC can flexibly allocate pause times across congested ports, which are not only compatible with existing PFC but also do not require per-flow states. We implemented FAFC in P4 programmable switches, showing it as lightweight flow control method that is portable for implementation in hardware. Remarkably, our large-scale simulations illustrate that compared to traditional PFC, FAFC improves the average FCT slowdown and 95% FCT slowdown by 10.6% and 23.3%, respectively, under Hadoop workload when performing HPCC congestion control.
Chengdi Lu, Yuang Chen, Fangyu Zhang et al.· IEEE Transactions on Network...· 0 citations
The rapid emergence of mission-critical applications has shifted network requirements toward strict end-to-end deterministic delay guarantees. While packet-switching infrastructures provide flexibility and scalability, achieving predictable delay remains challenging in the presence of arrival jitter caused by traffic shaper implementations, which are used to regulate packet transmission intervals, and initial timing offsets during connection establishment. This paper presents a theoretical framework for analyzing delay performance in periodic credit-based input-queued switches under bounded arrival jitter, where the jitter does not exceed the transmission period T. We prove that the maximum queueing delay is bounded by 2T when the initial offset Φ = 0, and by 3T during the pre-connection establishment phase, where the initial phase offset between the arrival process and the credit assignment is not yet fixed. Furthermore, we show that the probability that the delay exceeds a given threshold prior to connection establishment is upper-bounded by a distribution obtained via convolution of the Φ=0 case. Numerical results validate the derived bounds and demonstrate that the framework enables reliable worst-case delay estimation without exhaustive simulations.
The rapid evolution of 5G and emerging 6G networks requires optical access systems to support immersive extended reality (XR) services with stringent quality-of-service (QoS) requirements, like ultra-low latency and high bandwidth. However, conventional dynamic bandwidth allocation (DBA) schemes in passive optical networks (PONs) allocate upstream bandwidth solely based on reported queue occupancy, without considering the unique characteristics of XR traffic. To address these limitations, we propose an XR-aware Predictive (XP)-DBA scheme that integrates XR traffic prediction, deadline-aware scheduling, adaptive grant control, and a cycle-controller to proactively allocate bandwidth, prioritize latency-critical packets, and limit polling-cycle growth. We also derive closed-form analytical expressions to characterize XR-specific stability and delay feasibility in PON systems. We evaluate XP-DBA under standardized and burst-enhanced XR traffic models across varying XR user densities and transmission distances of up to 100 km. The results show that XP-DBA will reduce latency, jitter, and polling-cycle time while increasing throughput and supporting higher XR user densities under heavy network loads without violating XR delay bounds. These findings establish XP-DBA as an efficient and scalable scheduling solution for next-generation immersive XR services over long-reach optical access networks.
Akhilesh Patel, Y. Singh· IEEE Transactions on Network...· 0 citations
Abstract The increasing demand for high-speed data transmission has accelerated the adoption of multistage optical switching architectures. Cascaded buffered optical switches improve scalability and routing efficiency but suffer from packet contention and limited buffer capacity, leading to increased blocking probability, packet loss, and transmission delay under heavy traffic. This paper presents an analytical performance evaluation of cascaded buffered optical switching networks by modeling each switching node as a finite-capacity queue. Mathematical models are developed to analyze blocking probability, throughput, and average end-to-end delay, along with a generalized expression for cumulative blocking probability across multiple switching stages. The impact of traffic intensity, buffer size, and the number of cascaded switches on network performance is systematically investigated. Simulation results show that increasing buffer capacity significantly improves network performance by reducing packet loss and maintaining high throughput. For a buffer size of 16 packets, throughput decreases by only about 10 % as the number of cascaded switches increases from 5 to 20, demonstrating good scalability. Although end-to-end delay increases with additional switching stages, it remains within acceptable limits for high-speed optical communication systems. The proposed analysis provides useful guidelines for buffer dimensioning and the design of scalable next-generation optical switching networks.
Amit Sinha, D. Bhardwaj, Vaibhav Shukla· Journal of optical communica...· 0 citations
Evaluation on representative workloads demonstrates that P2CS achieves performance comparable to in-network mechanisms while significantly reducing complexity and cost, and requires minimal software changes making it readily deployable in today's datacenter infrastructure.
Ali Munir, Xiaolin Pang, Junyi Zhang· Conference on Applications,...· 0 citations
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