What is Network Latency and How to Improve It?

Let me start with a familiar scene – you excitedly click on a video shared by a friend on social media. But instead of instantly playing, you stare for 10-15 seconds at the buffering animation waiting for it to start. The lag is enough to suck out all the eagerness. We experience similar delays daily across apps and websites that hamper our productivity.

As an avid online gamer myself, I realized latency can literally make or break the experience. During an intense multi-player battle scene, the slightest lag disorients gameplay and could result in defeat. The frustration from losing due to lag rather than skill is indescribable!

Through my technical career across startups and enterprises, I understood the criticality of latency in delivering business outcomes. As per research by Akamai, a 100 millisecond delay in website load time can cause up to 7% loss in conversions. For latency-sensitive applications like stock trading, every microsecond counts.

This article takes a deep dive into latency – what creates it, techniques to measure it and most importantly how we can contain it. Buckle up to uncover the secrets of the lag!

Demystifying Network Latency

We often use terms like latency, bandwidth and throughput loosely when discussing internet connectivity. However as technical metrics, they have distinct definitions. Let‘s clarify them one by one:

Latency is the time elapsed for a packet of data to travel from source to destination across a network. It indicates your network‘s responsiveness. High latency causes delays.

Bandwidth refers to the maximum data transfer capacity available. It determines how much data you can load concurrently. Insufficient bandwidth throttles speed.

Throughput is the actual rate of data delivered over a network. Throughput is affected by both available bandwidth and underlying latency.

As per Cisco‘s analysis, bandwidth alone can no longer provide competitive advantage for user engagement in Web 2.0 era. Delivering rich, interactive digital experiences requires emphasis on driving lower latencies.

Key Sources of High Latency

Latency gets introduced into your network due to a variety of factors:

1. Physical Distance

Greater geographical distance between user and application hosting site leads to increased transit time through more network hops. This amplifies base latency. Real world measurements by Verizon indicate ~100 milliseconds of added one-way delay for every 300 kilometers of fiber route.

2. Overloaded Links

When demand exceeds capacity on network links due to bandwidth congestion or router processing constraints, queuing and buffering manifest as swollen latency. Metro networks are more prone due to shared capacity.

3. Protocol Inefficiencies

Legacy network protocols like TCP were designed for reliable transmission but have lag in reaction to dynamic path changes. Newer protocols attempt to reduce handshake steps. Migrations help unless hardware-constrained.

4. Concentrated Processing

Centralized application architecture concentrates load on few servers. This gets magnified with scale. Fragmenting workload across distributed edges avoids forcibly pulling data over distances.

5. Chatty Applications

Poorly optimized application logic and database queries result in excessive roundtrips. Caching, batching, parallelism, and shifts left in processing reduce chattiness and consequently latency.

In general, target latency below 100 milliseconds for responsive applications, under 10 ms for highly interactive ones as games and less than 1 ms for algorithmic trading systems.

Measuring the Latency in Your Network

While 100% elimination of lag is impossible, quantifying current latency baselines and continuously monitoring metrics provides insight into both application performance and infrastructure headroom across different use cases.

1. Round-trip Monitoring

Simplest method is to use ping on Windows or fping on Linux to get RTT at protocol layer. For service-level insight, use curl or wget to fetch a landing resource and trace DNS, connection establishment, and transfer times.

2. Hop-by-hop Analysis

Traceroute reveals RTT to each network node along end-to-end path by manipulating TTL expiry. MTR combines ongoing latency + loss measurement capability. Both help identifying problematic hops.

3. Passive Traffic Inspection

Analyzing flow metadata via monitors attached to router SPAN ports uncovers forwarding delays between various site pairs over sampling intervals. This works for baseline infra visibility.

4. Active Synthetic Probes

Dedicated monitoring agents installed at vantage points across networks emulate user traffic and measure vital KPIs like session connectivity, transfer rates, latency for ongoing performance management.

Why High Latency Matters

While the quest for lower latency may seem academic, further analysis underscores why it matters for end user satisfaction and business returns:

1. Higher Latency = More abandoned sessions

  • 53% mobile users abandon sites taking over 3s to load (Google)
  • A 2 second slowdown reduces traffic by 15% (Akamai)
  • 10 second loading time sees 90% failure rate (Nielsen Norman)

2. Even minor delays disrupt real-time usage

  • 250 ms lag spikes degrade call quality (Cisco)

  • 100 ms additional lag doubles MMOs server load (Kwon et al)
  • 68% users expect < 2 second latency for live-streams (Conviva)

3. Algorithmic use cases have ultra-low tolerance

  • Peak colocation latency must be under 30 microseconds for algorithmic traders as per MIT findings.
  • More than 40 ms latency can cause failures in industrial IoT predictive maintenance use cases.

Optimization Avenues to Reduce Latency

With wide evidence on how latency impacts services, addressing it requires a combination of below strategies:

1. Distribute Globally

Deploying apps closer to user clusters minimizes distance-induced lag. This leverages geo-localization and anycast IP techniques.

2. Migrate to Edge Computing

Process data at modular microservices hosted at edge servers near consumers instead of transferring across the core needlessly.

3. Choose Direct Routes

Carefully selecting peering partners and SD-WAN overlays circumvents congested IXPs. MPLS Fast Reroute provides sub-50ms convergence on failures.

4. Select Hyper-Optimized Protocols

Google‘s TCP BBR, HTTP/3‘s QUIC outshine TCP throughput over high-latency networks through AI-powered congestion control and loss resilience.

5. Refactor Code for Speed

Simplify application logic, enable compression, caching, server-push, lazy loading to transfer bare essential objects sooner. Measure consequent latency reduction.

6. Upgrade Constrained Gear

Legacy routers and middleboxes with dated networking silicon unable to sustain line-rates bring artificial constraints.

7. Horizontally Scale Resources

Stateless auto-scaling of app instances counters increased loads rather than concentrating delay inducing work on few servers.

There is no single magic bullet when tackling latency across diverse applications, hardware and protocols. An integrated approach is key.

Key Takeaways

Delivering responsive user experiences is vital for customer acquisition and retention in competitive digital landscape today. Latency plays a pivotal role but is often neglected.

My key recommendations for organizations struggling with latency are:

  • Invest in modern infrastructure designed for speed

  • Adopt distributed cloud-native app patterns

  • Refactor legacy apps by offloading workloads

  • Closely monitor all services for latency SLA breaches

  • Keep optimizing – latency benchmarks continually tighten!

I hope this guide offered you a comprehensive overview of managing latency for stellar digital delivery. Share your thoughts or queries in comments below.