What is Latency? Understanding Network Latency, Causes, and How to Fix High Latency

TLDR: Network latency is the time delay between when a data packet is sent and when it’s received—essentially measuring the amount of time it takes for information to pass through a network from source to destination. Latency is the delay you experience when you ping a server, measured in milliseconds as round-trip time. Higher latency causes network performance degradation, impacting file transfers, cloud applications, and real-time communications. While latency is the time constrained by the speed of light traveling through fiber optic cable infrastructure, organizations can reduce latency through optimized routing, content delivery networks, and minimizing the number of network hops data packets must traverse. However, to truly fix latency issues affecting long-distance data transfers, enterprises need solutions that overcome TCP’s fundamental limitations. Understanding network latency issues, their causes, and how to measure latency enables organizations to improve network performance. IBM Aspera’s FASP protocol addresses operational latency constraints by maintaining consistent throughput regardless of distance, eliminating the performance penalties that increase latency on traditional file transfer protocols across global networks.

Latency is the response time between a user’s action and the system’s reaction—how long it takes data to travel from point A to point B and back again. Often referred to as round-trip time (RTT) or network delay, latency plays a critical role in the performance of file transfers, cloud applications, and real-time communication. High latency leads to processing lag, inefficiencies, and a drop in overall productivity.

While increasing bandwidth might seem like a quick fix, it won’t resolve issues tied to signal delay or data transmission delay. IBM Aspera, powered by its patented FASP® protocol, helps businesses bypass these latency roadblocks and transfer data quickly, reliably, and securely—no matter the distance. 

What is Latency?

Latency is the amount of time that it takes for a signal to travel from a computer to a remote server and back again. It describes the amount of delay on a network or internet connection. When it comes to measurement, low latency implies there are no or almost no delays, while high latency implies there are many delays. 

Many of today’s businesses are reliant upon cloud applications to tackle critical tasks. Coworkers are not only communicating across distributed worksites, but they also depend on cloud-based management tools to access information, share files, and transfer data. High latency slows down these processes, creating inefficiencies that negatively impact employee and business productivity.

Latency Impact Comparison

Understanding Network Latency: Impact Across Different Applications

Latency Range	Network Performance	Real-World Impact	Use Cases Affected	How to Improve
<20ms	Excellent	Imperceptible time delay	Gaming, VoIP, video conferencing	Maintain with fiber optic infrastructure
20-50ms	Good	Minimal ping delay, responsive	Web browsing, standard applications	Optimize routing, use content delivery networks
50-100ms	Moderate	Noticeable time delay in interactions	File transfers begin degrading	Reduce latency via network optimization
100-200ms	Fair	Visible lag in real-time applications	VoIP quality drops, gaming affected	Fix latency with better routing, reduce hops
200-500ms	Poor	Significant operational latency	File transfers severely impacted	Implement Aspera or reduce network distance
>500ms	Very Poor	Unacceptable network latency issues	TCP throughput collapses	Requires protocol-level solution like FASP

Key Factors Affecting Latency:

• Physical Distance: Data packets traveling through fiber optic cable are limited by the speed of light (~200,000 km/second in fiber)
• Network Hops: Each router a data packet must pass through adds time delay
• Jitter: Variability in latency is the delay consistency; high jitter degrades network performance
• Causes of Network Latency: Distance, router processing, network congestion, inadequate fiber optic infrastructure

Why This Matters: While you can measure latency with tools like ping, understanding that latency is the time it takes data to travel fundamentally constrained by physics helps explain why simply adding bandwidth won’t fix latency problems. The amount of time it takes for signals to pass through a network increases proportionally with distance, which is why IBM Aspera’s FASP protocol becomes essential for maintaining throughput on long-distance transfers where higher latency would otherwise cripple TCP-based systems.

What is Latency in Gaming?

In gaming, latency is often measured in milliseconds and referred to as “ping.” It plays a massive role in system responsiveness, particularly in competitive or real-time online games.

Common Latency Impacts in Gaming:

• Processing lag between a player’s command and the game’s reaction
• Delayed hit registration or movement
• Signal delay causing “rubberbanding” or teleporting effects
• Sudden disconnects or server timeout issues

Gamers aim for latency below 50ms for an optimal experience. Latency spikes can be caused by distant servers, poor network infrastructure, or heavy background traffic—any of which reduce real-time feedback and impact gameplay quality.

Latency vs. Bandwidth: What’s the Difference?

Bandwidth is what most internet service providers advertise on their plans, also referred to as download speed. It measures how much data can be sent to your computer. 

Latency measures how long it takes a specific piece of data to reach your computer. High latency can actually offset the effectiveness of a high-bandwidth connection because these packets of information take longer to respond and clog the network. Many people try to offset this problem by purchasing more bandwidth. However, if a business doesn’t solve the underlying latency problem, they’ll continue to see the same lagging speeds even after buying more bandwidth.

How to Solve Latency Issues for File Transfers

The larger a file or data set is, the more time it takes to be sent on a high latency network. In order to solve the problem, you need a file transfer protocol that efficiently manages transfers regardless of high latency or high bandwidth networks.

While traditional methods for transferring data across the internet all rest on the transfer control protocol, it is not the most efficient for long-distance transfers. It may work fine for short distances, but it can be greatly impacted by latency due to the mechanism it uses for data transfer. 

To overcome the latency challenge with transfer, companies need file transfer software that uses a better, more improved protocol that implements flow, congestion controls, and compensation for data loss.

What is Latency in Simple Terms?

Latency is the delay between cause and effect—specifically, network latency is the time it takes for a data packet to travel from your computer to a remote server and back again. Think of latency as the time delay you experience when you ping a website: you send a request, it travels through the network, reaches the destination, and returns a response. The amount of time it takes for this round trip is your latency, typically measured in milliseconds.

In simple terms, latency is the delay you feel when actions don’t happen instantly. When you click a button on a website and wait for the page to load, you’re experiencing latency. When gamers complain about “lag,” they’re describing higher latency that creates a time delay between their actions and the game’s response. While bandwidth determines how much data can pass through a network simultaneously, latency determines how quickly each piece of data makes the journey.

The physical reality underlying network latency connects directly to the speed of light traveling through fiber optic cable. Since data packets must physically travel through infrastructure—copper wires, fiber optic cables, undersea cables across oceans—distance creates inherent time delay. A data packet traveling from New York to London must cover roughly 5,500 kilometers, which at the speed of light through fiber optic (approximately 200,000 km/second) requires at least 27.5 milliseconds one-way. This is the absolute minimum latency physics allows, before accounting for router processing, network congestion, or the multiple network hops data must pass through.

Network latency issues become particularly problematic for real-time applications and global data transfers. Video conferencing relies on low latency to avoid awkward delays in conversation. Online gaming requires sub-50ms latency for responsive gameplay. Cloud applications depend on minimal time delay to feel snappy and local. Financial trading systems demand the lowest possible operational latency where milliseconds translate to millions in trading advantages. Understanding that latency is the time constrained by physical laws helps explain why geographic distribution of servers, content delivery networks, and protocol optimization all matter for network performance.

What is a Good Latency?

A good latency depends entirely on the application, but generally, network latency below 50 milliseconds provides excellent network performance for most use cases. For web browsing and standard business applications, latency under 100ms feels responsive and users typically won’t notice time delay. However, specific applications have different tolerance thresholds for what constitutes acceptable ping times and operational latency.

Gaming represents one of the most latency-sensitive applications. Competitive gamers seek network latency below 20ms for optimal performance, with 50ms representing the upper limit for good responsiveness. Above 100ms, players experience noticeable lag where actions don’t register immediately, creating disadvantages in fast-paced games. First-person shooters, real-time strategy games, and fighting games are particularly sensitive to higher latency because split-second timing determines success. When you measure latency for gaming with a ping command, you’re directly assessing whether the network can support real-time gameplay without frustrating time delays.

Voice over IP (VoIP) and video conferencing require latency under 150ms for natural conversation flow. The International Telecommunication Union recommends maximum one-way latency of 150ms for acceptable voice quality, which translates to roughly 300ms round-trip time. Beyond this threshold, conversations develop awkward pauses where participants talk over each other because they can’t hear responses in real-time. Video conferencing adds visual desynchronization issues when higher latency causes audio and video streams to fall out of alignment. Organizations can reduce latency for these applications by deploying content delivery networks, optimizing network routing, and prioritizing real-time traffic through quality-of-service configurations.

File transfer applications tolerate higher absolute latency but suffer dramatic throughput degradation on long-distance, high-latency connections. While a 200ms network latency might not feel terrible for web browsing, it devastates TCP-based file transfer performance. TCP’s windowing mechanism means that throughput = window size / round-trip time, so doubling latency cuts throughput in half regardless of available bandwidth. This explains why organizations attempting to transfer large files internationally experience transfer times measured in days despite purchasing expensive high-bandwidth connections. To fix latency impact on file transfers, enterprises need protocols like IBM Aspera’s FASP that maintain consistent throughput regardless of network latency.

Measuring good latency requires understanding jitter alongside average ping times. Jitter measures variability in latency—if your network alternates between 50ms and 200ms latency, applications experience inconsistent network performance even though average latency might appear reasonable. Low jitter (under 30ms variation) alongside low latency provides the consistency applications need. Network monitoring tools that measure latency should track both average ping times and jitter to accurately assess whether operational latency meets application requirements. Organizations seeking to improve network performance must address both reducing baseline latency and minimizing jitter to deliver consistent, predictable network behavior.

How Do I Fix High Latency?

To fix latency issues, organizations must first identify the causes of network latency through systematic measurement and analysis. Use ping commands to measure latency to various destinations, traceroute to identify which network hops contribute most time delay, and continuous monitoring to detect when network latency issues occur. Understanding whether higher latency stems from physical distance, network congestion, poor routing, or infrastructure limitations determines which solutions will reduce latency effectively.

For operational latency improvements within your control, optimize your local network infrastructure. Replace aging routers and switches that introduce processing delays as each data packet must pass through them. Ensure adequate bandwidth provisioning so network congestion doesn’t increase latency during peak usage. Implement quality-of-service (QoS) policies that prioritize latency-sensitive traffic like VoIP and video conferencing over less time-critical data. Upgrade to fiber optic connections rather than copper where possible, as fiber optic cable provides lower inherent latency and higher throughput capacity. While these improvements help reduce latency, they cannot overcome the fundamental constraint that latency is the time limited by the speed of light through physical infrastructure.

For applications serving geographically distributed users, content delivery networks (CDNs) represent a powerful strategy to improve network latency. CDNs cache content on servers distributed globally, allowing users to retrieve data from nearby locations rather than traversing intercontinental distances. When a data packet only needs to travel 100 kilometers to a local CDN edge server rather than 10,000 kilometers to a central data center, the amount of time it takes drops dramatically. CDNs work particularly well for static content delivery but cannot address network latency issues for real-time data generation or bidirectional file transfers where content can’t be pre-positioned.

Route optimization can reduce latency by ensuring data packets take the most direct network path rather than circuitous routes through suboptimal peering arrangements. Internet backbone providers don’t always route traffic efficiently—your data might travel from New York to Los Angeles via Chicago simply due to peering relationships between carriers. Software-defined WAN (SD-WAN) technologies can dynamically select optimal paths based on measured latency, automatically routing traffic through the fastest available connection. This approach helps fix latency when network topology inefficiencies add unnecessary time delay to what should be shorter paths.

However, to fundamentally fix latency impact on file transfer throughput, protocol-level solutions become necessary. Traditional TCP cannot maintain throughput on high-latency connections regardless of available bandwidth due to its windowing and acknowledgment requirements. IBM Aspera’s FASP protocol solves this by implementing UDP-based transfer with custom reliability mechanisms optimized for long-distance, high-latency networks. Where TCP suffers exponential throughput degradation as latency increases, FASP maintains consistent performance. Organizations transferring large datasets globally cannot truly fix latency using network optimization alone—they need protocols designed specifically to neutralize latency’s impact on throughput, which is precisely what Aspera delivers.

What Does a High Latency Mean?

High latency means increased time delay throughout your network operations, fundamentally limiting how quickly data can pass through a network regardless of available bandwidth. When network latency exceeds acceptable thresholds, users experience slow application responsiveness, delayed file transfers, poor video conference quality, and frustrating interactions with cloud services. Higher latency doesn’t just slow things down slightly—it can completely cripple network performance for certain applications, particularly those requiring real-time responsiveness or involving long-distance data transfer.

For enterprise file transfers, high latency creates a particularly insidious problem because the relationship between latency and throughput isn’t linear—it’s exponential. TCP-based transfer protocols suffer dramatic throughput collapse as network latency increases. A file transfer that might complete in 10 minutes on a local network with 5ms latency could require 100+ hours on an intercontinental connection with 150ms latency, despite identical bandwidth availability. This occurs because TCP must wait for acknowledgment packets to return before sending additional data, and the amount of time it takes for these acknowledgments to traverse high-latency networks severely limits throughput. Organizations cannot solve this problem by purchasing more bandwidth because latency is the delay that bandwidth cannot overcome.

High latency impacts real-time applications through visible quality degradation that frustrates users and impedes productivity. Video conferences with higher latency develop awkward conversational pauses where participants unknowingly talk over each other. VoIP calls accumulate echo and audio delay that makes natural conversation impossible. Remote desktop sessions become sluggish where mouse movements and keyboard inputs lag behind their on-screen effects. Each interaction that should feel instantaneous instead introduces perceptible time delay that adds cognitive load and reduces efficiency. When multiple team members experience these network latency issues simultaneously, collaboration suffers and productivity drops measurably.

The causes of network latency include both factors within organizational control and fundamental physical constraints. Distance represents the immutable factor—since data travels at the speed of light through fiber optic cable (approximately 200,000 km/second), transcontinental transfers face inherent latency floors around 50-100ms based purely on physics. Network infrastructure quality matters tremendously: aged routers that process data packets slowly, network congestion that forces queuing delays, and circuitous routing that adds unnecessary distance all increase latency avoidably. To measure latency accurately, organizations need comprehensive monitoring that identifies which factors contribute most to their specific network latency issues, distinguishing between controllable infrastructure problems and unavoidable physical distance constraints.

Jitter—variability in latency—often proves more disruptive than consistently high latency. Applications can sometimes adapt to stable, predictable time delay, but when network latency fluctuates rapidly, nothing works reliably. A video stream might play smoothly at 200ms latency if that latency remains constant, but if latency randomly varies between 50ms and 300ms, buffering and quality degradation become constant frustrations. To improve network performance, addressing jitter through infrastructure upgrades and traffic prioritization sometimes matters more than reducing absolute latency, particularly for applications with adaptive buffering capabilities.

Understanding that high latency fundamentally limits what traditional protocols can achieve helps explain why enterprises investing in network optimization often see disappointing results for international file transfers. You can reduce latency somewhat through better routing, you can minimize jitter through QoS policies, you can upgrade to fiber optic infrastructure—but when transferring data between New York and Tokyo, physics dictates minimum latency around 80-100ms. At those latency levels, TCP-based throughput collapses regardless of available bandwidth. This is precisely why IBM Aspera developed FASP: to maintain full throughput even when higher latency would cripple traditional protocols, finally breaking the connection between network latency and transfer performance.

Key Takeaways: Essential Network Latency Knowledge: Causes, Impact, and Solutions

Understanding Network Latency Fundamentals

• Network latency is the time delay between sending data and receiving a response, measured in milliseconds as round-trip time
• Latency is the delay you experience when you ping a server—it measures how long a data packet takes to pass through a network
• The amount of time it takes for data to travel is fundamentally limited by the speed of light through fiber optic cable infrastructure
• Latency is the time constrained by physics: data traveling through fiber optic at ~200,000 km/second creates inherent delays based on distance

Measuring and Assessing Latency

• Use ping commands to measure latency to specific destinations, revealing the time delay in network communications
• Tools like traceroute identify which network hops contribute most to operational latency as data packets traverse routers
• Good latency for gaming: <50ms | For VoIP: <150ms | For web apps: <100ms | For file transfers: depends on throughput requirements
• Jitter (latency variability) often impacts network performance more severely than high but consistent latency

Causes of Network Latency

• Physical distance: Data must physically travel through fiber optic cable, with distance directly determining minimum possible latency
• Network hops: Each router a data packet must pass through adds processing time delay
• Network congestion: Bandwidth saturation forces data packets into queues, increasing time delay
• Infrastructure quality: Aging equipment and suboptimal routing increase operational latency unnecessarily

Impact of Higher Latency

• Real-time applications: Video conferencing, VoIP, and gaming become unusable when network latency exceeds application tolerance
• File transfer throughput: TCP-based transfers suffer exponential performance degradation as network latency increases
• Cloud application responsiveness: Higher latency makes cloud services feel sluggish even with adequate bandwidth
• Productivity costs: Time delay in every interaction accumulates to significant efficiency losses across organizations

Network Performance and Throughput

• Bandwidth measures capacity (how much data can pass through a network); latency measures speed (how quickly it arrives)
• Higher latency limits throughput regardless of available bandwidth due to TCP’s windowing and acknowledgment requirements
• The relationship: throughput = window size / round-trip time means doubling latency cuts throughput in half
• Organizations cannot fix latency impact on file transfers by simply purchasing more bandwidth

How to Reduce Latency

• Optimize local infrastructure: Upgrade routers and switches that introduce unnecessary processing delays
• Implement quality-of-service (QoS): Prioritize latency-sensitive traffic to reduce time delay for critical applications
• Deploy content delivery networks: CDNs reduce latency by serving content from geographically distributed servers
• Improve routing: Ensure data packets take the most direct network path rather than circuitous routes
• Upgrade to fiber optic: Fiber optic cable provides lower latency and higher throughput than copper alternatives

How to Fix Latency Issues

• Measure latency systematically to identify whether issues stem from infrastructure, routing, or physical distance
• Address controllable factors: network congestion, inefficient routing, and aging equipment that increase latency avoidably
• Accept physical constraints: Some latency is unavoidable when transferring data across continents due to speed of light limits
• For file transfers: Traditional optimization can only reduce latency marginally—protocol-level solutions are required for breakthrough performance
• Implement monitoring: Continuous measurement helps detect when network latency issues emerge and need attention

Latency vs. Bandwidth: Critical Distinction

• Bandwidth is how much water flows through a pipe; latency is how long it takes for the first drop to arrive
• Increasing bandwidth doesn’t fix latency problems—adding capacity doesn’t reduce time delay
• Network performance requires both adequate bandwidth and low latency for optimal throughput
• Organizations often purchase expensive bandwidth upgrades that fail to improve performance because latency remains the bottleneck

Content Delivery Networks and Geographic Distribution

• CDNs improve network latency by caching content closer to users, reducing the distance data packets must travel
• Strategic server placement can reduce latency from 200ms+ to sub-50ms for geographically distributed users
• Edge computing extends this concept by processing data locally rather than forcing round trips to distant data centers
• However, CDNs cannot address latency issues for bidirectional file transfers or real-time data generation

Protocol-Level Solutions for File Transfer

• TCP-based protocols cannot overcome higher latency impact on throughput regardless of optimization efforts
• IBM Aspera’s FASP protocol maintains consistent throughput even when network latency would cripple TCP
• While you can reduce latency somewhat through network optimization, only protocol innovation truly eliminates its impact
• Organizations requiring global file transfer at scale need solutions designed specifically to neutralize latency constraints

Enterprise Decision Framework

• For local networks: Focus on reducing latency through infrastructure upgrades and proper QoS implementation
• For geographically distributed teams: Deploy CDNs and regional servers to minimize distance data must travel
• For real-time applications: Network latency under 50-100ms is essential; optimize routing and prioritize traffic
• For global file transfers: Accept that traditional optimization cannot fix latency impact; implement Aspera FASP for breakthrough performance
• Monitor continuously: Regular measurement helps identify when operational latency degrades and requires intervention

Understanding network latency and its causes enables organizations to make informed infrastructure decisions. While you can reduce latency through optimization and architectural improvements, some time delay remains unavoidable when data must pass through a network across long distances at the speed of light through fiber optic infrastructure. The critical insight: for applications where higher latency severely degrades network performance—particularly global file transfers—only purpose-built protocols like IBM Aspera’s FASP can truly fix latency impact by maintaining throughput regardless of round-trip time. Organizations shouldn’t just attempt to reduce latency; they should implement solutions that neutralize latency’s effect on throughput entirely, which is precisely what PacGenesis helps enterprises achieve through Aspera implementations.

How Aspera Improves Performance

With fast file transfer and high-speed solutions built on their award-winning FASP protocol, IBM Aspera software enables secure movement of data at line speeds, regardless of latency or geographic distance between the sender and receiver.

The IBM Aspera FASP protocol uses a unique and patented approach that enables maximum speed without network saturation. With it, your company gains a higher degree of reliability with an automatic resume and restart from any point of interruption. Aspera enables its users to predict transfer time, regardless of distance or network conditions.

Contact PacGenesis to Learn More

PacGenesis provides professional services for the implementation of all IBM Aspera file transfer solutions. As an IBM Gold Business Partner with over 10 years of industry experience, we have helped businesses like yours overcome high latency issues and increase productivity with file transfer software. To learn more about how Aspera can help your business, contact us today.

 
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