Networking Metrics

About

Networking metrics are essential performance indicators that help assess the efficiency, reliability, and responsiveness of a system’s network. They play a crucial role in designing scalable, high-performance distributed systems and optimizing network infrastructure.

1. Latency

Latency is the time delay between when a request is made and when a response is received. It is measured in milliseconds (ms) and can impact system performance, user experience, and data transmission.

Latency can be classified into different types based on where it occurs:

1. Network Latency (End-to-End Delay)

2. Application Latency

3. Disk Latency (Storage Latency)

4. Database Latency

5. Memory Latency

1. Network Latency

The delay in transmitting data over a network from sender to receiver.

Causes of Network Latency

• Physical Distance → Longer distances take more time (e.g., sending data from the US to India).

• Congestion → High traffic on a network slows down data transmission.

• Packet Loss & Retransmission → Lost packets require resending, increasing latency.

• Bandwidth Limitations → Lower bandwidth means slower data transfer.

• Routing & Switching Delays → Time spent at intermediate routers and switches.

Formula for Total Network Latency

Network Latency = Transmission Delay + Propagation Delay + Processing Delay + Queuing Delay

Example Calculation

• Packet Size = 10 MB

• Bandwidth = 100 Mbps

• Distance = 3000 km

• Speed of Light in Fiber = 200,000 km/s

Transmission Delay = (10×8) / 100 = 0.8 seconds Propagation Delay = 3000 / 200000 = 0.015 seconds Total Latency ≈ 0.815 seconds (815 ms)

Optimization Techniques

• Use Content Delivery Networks (CDNs) to bring data closer to users.

• Reduce DNS resolution time (avoid unnecessary redirects).

• Optimize network routing to use faster paths.

2. Application Latency

The delay caused by an application while processing a request.

Causes of Application Latency

• Slow Backend Processing → Heavy computations or inefficient algorithms.

• Database Queries → Complex or unoptimized queries slow response time.

• API Call Delays → Waiting for responses from third-party APIs.

• Thread Blocking → Poor multi-threading can cause delays.

Application Latency Breakdown

Component	Definition	Optimization
Processing Time	Time for backend logic execution	Use efficient algorithms
Database Query Time	Time spent fetching data from the DB	Optimize queries, indexing
API Call Delay	Delay from external APIs	Use async API calls, caching

Formula for Application Latency

Application Latency = Processing Time + DB Query Time + API Call Delay

Example Calculation

• Processing Time = 100 ms

• DB Query Time = 200 ms

• API Call Delay = 300 ms

Total Latency = 100 + 200 + 300 = 600 ms

Optimization Techniques

• Reduce DB calls → Use caching (Redis, Memcached).

• Improve backend performance → Optimize algorithms, use parallel processing.

• Use Asynchronous Processing → Reduce blocking operations.

3. Disk Latency (Storage Latency)

The time delay in retrieving data from a storage device (HDD/SSD).

Causes of Disk Latency

• Mechanical Movements in HDD → Seek time, rotational delay.

• Slow SSD Response → NAND flash limitations.

• Large File Transfers → More data requires more time.

Disk Latency Breakdown

Component	Definition	Optimization
Seek Time	Time for HDD head to reach the data location	Use SSD instead of HDD
Rotational Delay	Time waiting for the correct disk sector	Use NVMe SSDs
Data Transfer Time	Time to read/write data	Optimize storage architecture

Formula for Disk Latency

Disk Latency=Seek Time + Rotational Delay + Data Transfer Time

Example Calculation

• Seek Time = 5 ms

• Rotational Delay = 3 ms

• Data Transfer Time = 2 ms

Total Latency = 5 + 3 + 2 = 10 ms

Optimization Techniques

• Use SSDs instead of HDDs.

• Optimize indexing and compression.

4. Database Latency

The delay in retrieving data from a database.

Causes of Database Latency

• Slow Queries → Poor indexing, large joins, unnecessary columns.

• Locks and Contention → Concurrent transactions blocking each other.

• Network Bottlenecks → Delays in transferring data from the database.

Database Latency Breakdown

Component	Definition	Optimization
Query Execution Time	Time taken to run a query	Optimize queries
Indexing Delay	Time spent searching without indexes	Use proper indexing
Lock Contention	Delays due to concurrent transactions	Use optimistic locking

Optimization Techniques

• Use indexes to speed up lookups.

• Avoid full-table scans.

• Optimize schema design to reduce joins.

5. Memory Latency

The delay in retrieving data from RAM.

Causes of Memory Latency

• Cache Misses → Data not found in L1/L2 cache.

• Slow RAM Speeds → Older DDR generations have higher latency.

• Memory Bus Contention → Multiple processes accessing memory simultaneously.

Optimization Techniques

• Use faster RAM (DDR5 vs DDR4 vs DDR3).

• Optimize memory allocation (avoid excessive swapping).

2. Bandwidth

The maximum rate of data transfer over a network connection in a given period.

Formula

Bandwidth = Total Data Transferred / Time Taken

Throughput vs Bandwidth: Bandwidth is the theoretical limit, whereas throughput is the actual amount of data transferred.

Bandwidth Throttling: Intentional reduction of bandwidth to control network congestion.

Optimization Techniques

• Use data compression (e.g., Gzip, Brotli for web pages).

• Optimize TCP window size for large data transfers.

• Implement QoS (Quality of Service) policies to prioritize critical traffic.

3. Throughput

The actual amount of data successfully transmitted per unit time.

Formula

Throughput = Total Successful Data Received / Time Taken

Factors Affecting Throughput

• Network Congestion – Delay caused by excessive traffic overwhelming network bandwidth.

• Packet Loss – Data packets failing to reach their destination due to network issues.

• Hardware Limitations – Performance bottlenecks due to outdated or underpowered network devices.

Optimization Techniques

• Use Load Balancing to distribute traffic.

• Reduce network bottlenecks (e.g., upgrade network hardware).

• Implement TCP optimization (e.g., TCP Fast Open, congestion control algorithms).

4. Packet Loss

The percentage of data packets that fail to reach their destination.

Formula

Packet Loss(%) = (Lost Packets / Total Packets Sent) × 100

Causes

• Network Congestion – Delay caused by excessive traffic overwhelming network bandwidth.

• Faulty Hardware – Malfunctioning network devices leading to degraded performance or connectivity issues.

• Misconfigured Routers/Switches – Incorrect network settings causing inefficient routing, bottlenecks, or connectivity failures.

Optimization Techniques

• Use redundancy mechanisms like Forward Error Correction (FEC).

• Implement packet prioritization for critical data.

• Optimize MTU (Maximum Transmission Unit) size to prevent fragmentation.

5. Jitter

Variation in latency over time, causing delays in data packet arrival.

Formula

Jitter = ∣T2−T1∣

where T1 and T2 are arrival times of two consecutive packets.

Impact

• Causes poor voice/video quality in real-time applications (VoIP, Zoom, gaming).

• Leads to buffering issues in streaming services.

Optimization Techniques

• Use Jitter Buffers to smooth packet delivery.

• Implement Traffic Shaping to prioritize real-time data.

• Reduce network congestion using QoS techniques.

6. Connection Establishment Time

The time taken to establish a network connection (e.g., TCP handshake).

Formula

Connection Time = DNS Resolution Time + TCP Handshake Time + TLS Handshake Time

Optimization Techniques

• Use persistent connections (e.g., keep-alive in HTTP/2).

• Implement TLS session resumption to speed up HTTPS connections.

• Optimize DNS resolution using caching and fast resolvers.