Protocol Support

Understanding UDP and RTMP protocols for video ingestion.

Table of contents

1. Supported Protocols
2. UDP Multicast
   1. Overview
   2. URL Format
   3. Examples
   4. Characteristics
   5. Network Requirements
   6. Configuration Steps
   7. Advantages
   8. Limitations
   9. Troubleshooting UDP
3. RTMP Streaming
   1. Overview
   2. URL Format
   3. Examples
   4. Characteristics
   5. Port Configuration
   6. Authentication
   7. Configuration Steps
   8. Advantages
   9. Limitations
   10. Troubleshooting RTMP
4. Protocol Comparison
   1. When to Use UDP
   2. When to Use RTMP
5. Protocol Specifications
   1. UDP Multicast
   2. RTMP
6. Network Configuration
   1. Bandwidth Requirements
   2. Firewall Configuration
7. Best Practices
   1. For UDP Multicast
   2. For RTMP
8. Diagnostic Commands
   1. UDP Testing
   2. RTMP Testing
9. Related Documentation

Supported Protocols

Encora Stream supports two primary protocols for ingesting live video streams:

• UDP Multicast: Traditional broadcast workflow protocol
• RTMP: Internet-based streaming protocol

UDP Multicast

Overview

UDP (User Datagram Protocol) multicast is widely used in professional broadcast environments for transporting MPEG-TS streams over IP networks.

URL Format

udp://@[multicast-address]:[port]

Examples

udp://@239.1.1.1:5000
udp://@239.255.0.1:1234
udp://@225.100.100.100:5004

Characteristics

Network Requirements

Multicast Routing:

• Network switches must support IGMP (Internet Group Management Protocol)
• Routers must be configured for multicast forwarding
• VLANs may require multicast configuration

Bandwidth:

• Dedicated network bandwidth for video traffic
• Typical: 5-15 Mbps per HD stream
• Higher for 4K content (25-50 Mbps)

Quality of Service (QoS):

• Prioritize video traffic
• Minimize packet loss
• Reduce jitter and latency

Configuration Steps

1. Verify Network Support

Check if multicast is enabled:

# On Linux server
ip route show | grep multicast

2. Test Multicast Reception

Use ffprobe to verify stream:

ffprobe -v error -show_streams udp://@239.1.1.1:5000

3. Monitor Multicast Traffic

tcpdump -i eth0 host 239.1.1.1 and port 5000

Advantages

✅ Low Latency: Minimal delay from encoder to platform ✅ High Quality: No compression artifacts from protocol ✅ Network Efficient: One stream serves multiple receivers ✅ Professional Standard: Industry standard in broadcast

Limitations

❌ Network Dependent: Requires proper multicast configuration ❌ No Error Correction: Lost packets cannot be recovered ❌ Limited to LAN: Typically not routed over internet ❌ Complex Troubleshooting: Requires network expertise

Troubleshooting UDP

Issue: Stream not received

Check these items:

1. Multicast routing enabled

   ip route show | grep multicast
   

2. Firewall allows UDP

   sudo iptables -L -n | grep udp
   

3. Encoder is transmitting
   • Check encoder status
   • Verify output configuration
   • Monitor encoder network interface
4. Correct network interface
   • Verify interface receives multicast
   • Check IGMP membership
   • Monitor interface statistics

RTMP Streaming

Overview

RTMP (Real-Time Messaging Protocol) is a TCP-based protocol widely used for internet streaming, particularly with OBS, Wirecast, and cloud encoders.

URL Format

rtmp://[server]:[port]/[application]/[stream-key]

Examples

rtmp://encoder.example.com:1935/live/stream-key-123
rtmp://10.0.1.100:1935/live/channel01
rtmp://rtmp.streaming.com:1935/app/secret_key_xyz

Characteristics

Port Configuration

Default Port: 1935

Firewall Rules:

# Allow RTMP traffic
sudo iptables -A INPUT -p tcp --dport 1935 -j ACCEPT

Authentication

Stream Keys:

• Use strong, random stream keys
• Rotate keys periodically
• Keep keys confidential
• Monitor for unauthorized use

Example Stream Key Format:

live_event_2024_secure_a1b2c3d4e5f6

Configuration Steps

1. Test RTMP Connection

Use ffprobe:

ffprobe -v error rtmp://encoder.example.com:1935/live/stream-key

2. Monitor RTMP Stream

Use ffplay for testing:

ffplay rtmp://encoder.example.com:1935/live/stream-key

3. Check RTMP Server Logs

Review server logs for connection attempts and errors.

Advantages

✅ Internet Friendly: Works over standard networks ✅ Reliable: TCP ensures packet delivery ✅ Widely Supported: OBS, Wirecast, vMix, etc. ✅ Firewall Friendly: Uses standard ports

Limitations

❌ Higher Latency: TCP overhead adds delay ❌ Bandwidth Overhead: Protocol metadata ❌ Single Receiver: One-to-one connection ❌ Internet Dependent: Requires stable internet

Troubleshooting RTMP

Issue: Cannot connect to RTMP server

1. Verify server is reachable

   telnet encoder.example.com 1935
   

2. Check stream key
   • Verify stream key is correct
   • Check for typos
   • Ensure no spaces or special characters
3. Firewall configuration
   • Port 1935 must be open
   • Check both server and encoder firewalls
   • Verify NAT configuration if applicable
4. Encoder settings
   • Verify RTMP URL is correct
   • Check encoder output format (H.264 + AAC)
   • Ensure encoder is streaming

Protocol Comparison

When to Use UDP

Choose UDP multicast when:

• ✅ Operating in a controlled LAN environment
• ✅ Using professional broadcast equipment
• ✅ Lowest possible latency is critical
• ✅ Network supports multicast routing
• ✅ High-quality, uncompressed feed required

When to Use RTMP

Choose RTMP when:

• ✅ Encoder is remote or internet-based
• ✅ Using OBS, Wirecast, or similar software
• ✅ Network multicast is not available
• ✅ Need simple, reliable connection
• ✅ Working with content creators

Protocol Specifications

UDP Multicast

Technical Specifications:

RTMP

Technical Specifications:

Network Configuration

Bandwidth Requirements

UDP Multicast:

• Dedicated VLAN recommended
• QoS priority for video traffic
• No bandwidth multiplication (efficient)

RTMP:

• Requires upload bandwidth at encoder
• Download bandwidth at platform
• Each stream needs full bandwidth

Firewall Configuration

UDP Multicast:

# Allow multicast traffic
sudo iptables -A INPUT -p udp -d 224.0.0.0/4 -j ACCEPT

RTMP:

# Allow RTMP port
sudo iptables -A INPUT -p tcp --dport 1935 -j ACCEPT

Best Practices

For UDP Multicast

1. Use dedicated network for video traffic
2. Configure QoS to prioritize video
3. Test multicast routing before deployment
4. Monitor packet loss continuously
5. Document multicast groups used

For RTMP

1. Use strong stream keys for security
2. Monitor connection stability
3. Implement reconnection logic in encoders
4. Test with representative content before production
5. Keep backup RTMP servers for redundancy

Diagnostic Commands

UDP Testing

Check stream availability:

ffprobe -v error -show_streams udp://@239.1.1.1:5000

Monitor packets:

tcpdump -i eth0 host 239.1.1.1

Test playback:

ffplay udp://@239.1.1.1:5000

RTMP Testing

Check stream availability:

ffprobe rtmp://server:1935/live/stream-key

Test playback:

ffplay rtmp://server:1935/live/stream-key

Monitor connection:

netstat -an | grep 1935

Related Documentation

• Configuration Guide - Set up input streams
• Testing Guide - Verify stream functionality
• Best Practices - Optimization tips
• Troubleshooting - Common issues