1. Network Roles, IP Address and Capacity Planning

Overview

In traditional SDI facilities, signal planning was primarily concerned with router ports, cable routes and tie-lines. In IP facilities, addressing becomes part of the infrastructure design. 

Poor IP address planning can result in:

• Difficult expansion projects
• Route summarisation limitations
• Site-to-site connectivity challenges
• SDN integration difficulties
• Operational complexity

A well-designed IPAM strategy allows facilities to grow from tens to thousands of devices without requiring re-addressing. When designing an IP broadcast facility, it is important for an organisation to adequately plan and manage the IP addresses of their infrastructure. This document provides some key information on how to understand:

• The various network roles that are required for a modern IP broadcast facility
• How to plan an IP address schema to allow for:
  • Increases in network capacity
  • Increasing the number of IP broadcast facilities within an organisation 
• Using appropriate IP address ranges and subnet masks
• The benefits of adopting Lawo's IPAM structure

This document is applicable for audio and media infrastructure integrations. It assumes the reader is familiar with basic networking concepts, such as:

• Network traffic types: unicast, multicast and broadcast
• IP addresses

Assessing Key Network Requirements

Understanding Network Roles

A typical IP broadcast facility will require at least four fabrics which perform different roles:

• Base
  • e.g. switch hardware and PTP GMCs communication

• Broadcast Control / Management
  • e.g. HOME and/or vsmStudio control and configuration data communication

• Red Streaming Media
  • e.g. ST2110, RAVENNA audio, metadata, PTP, video traffic, etc.

• Blue Streaming Media
  • e.g. ST2110, RAVENNA audio, metadata, PTP, video traffic, etc.

A network fabric consists of multiple devices (switches, servers, control panels etc.) that are interconnected in a highly scalable, resilient, and efficient way. In addition to the fabrics listed above, some customers may require additional network fabrics, for example:

• Purple Streaming Media
  • Typically used for devices that support 2022-7 via a single interface
    • e.g. Riedel MediorNet FusioN (Embrionix emFUSION)

• Low Bandwidth Streaming Media
  
  • • e.g. NDI, SRT etc.

• Out-of-Band Management (OOB)
  • A dedicated network used for managing IT infrastructure independently from the main data or production network
    • e.g. network switch management ports, server 'lights out management' ports etc.

Understanding Device Count and Network Scaling

Most customers new to IP-based broadcasting usually start by designing a small facility, typically consisting of less than 50 endpoints in the Red/Blue streaming media fabrics. Once they have gained experience and are comfortable with operating and managing their infrastructure, they often choose to add capacity to the existing facility, build another IP facility, or both. At this point, it is important to understand some key IPAM best practices:

Understanding the minimum number of streaming media endpoints a facility will need to support and adding 20%, is a good indicator for the amount of IP addresses that will be required. Lawo advises that customers assume and plan for growth from the very beginning. This could be the original facility increasing network capacity by adding more switches and endpoints, or building multiple new IP facilities of any size. For this reason, Lawo encourages the use of a hierarchical addressing scheme for all network fabrics:

• Allocate a unique IP range to each IP facility
  • A facility's IP range can be divided into smaller ranges by a process called subnetting
    • Each fabric is assigned a unique range of IP addresses
      • Each fabric in the IP facility performs a specific network role
        
        • Each fabric's IP address range can be subnetted further into smaller ranges

By using this method of organising and allocating IP addresses, there is IP space for each fabric to accommodate future devices and facilities. Additionally, a hierarchical addressing scheme:

Understanding IP Address Ranges and Subnetting

Lawo encourages customers to use private IP address ranges as defined in RFC 1918 (IPv4) and RFC 4193 (IPv6. They are reserved for internal network use and cannot be routed over the Internet. Using them correctly ensures efficient network management, security, and scalability. 

Lawo advises customers to provide their own private IP address range for broadcast operations, for example, a /16 IP address range:

Lawo provides the following per-octet IP address structure as a foundation:

Customers planning to build multiple IP broadcast facilities should consider using a unique /16 IP range per IP facility. This can be achieved by assigning a unique number in the second octet of an IP range. The benefits to this approach include:

Use of 2nd Octet

• Makes it easier to identify individual IP facilities within an organisation.
• Makes it potentially easier to move equipment between IP facilities as only the second octet in the IP address may need to change.

Once an appropriate private IP range has been determined, the process of subnetting (or creating smaller blocks of IP ranges) and assigning them to the individual network fabrics can begin. Selecting an appropriate subnet mask avoids wasting IP addresses and ensures room for future expansion. Below is a table of common subnet masks:

The third octet in the IP address range can be appropriately subnetted and assigned to the network fabrics:

Understanding VLANs (Logical Segmentation)

For the majority of streaming media LVN fabrics, VLANs are not implemented. Instead, routed interfaces assigned to /30 networks are favoured. In Broadcast Control / Management fabrics however, VLANs can be paired with subnets to:

• Reduce the size of the failure domain
  • e.g. the amount of devices that will be affected in the event of network disruption
• Reduce the size of the broadcast domain and improve efficiency
• Improve network performance and security

There is no single 'best practice' to allocating VLANs in a Broadcast Control / Management fabric, however there are two good strategies to be aware of:

• A VLAN per device type
  • This method subnets the IP address range assigned to the Broadcast Control / Management fabric and creates networks and VLANs based on the devices by type:

• • • VLAN 10: Engineering terminals
    • VLAN 11: HOME servers
    • VLAN 21: vsmStudio servers
    • VLAN 22: vsmGadget servers
    • VLAN 23: vsmStudio control panels
    • VLAN 24: vsmStudio control panels
    • VLAN 31: XCS servers
    • VLAN 41: Audio consoles (mc²)
    • VLAN 42: Radio consoles (crystal, diamond)
    • VLAN 51:..edge blades
    • VLAN 61: HOME Apps servers
    • VLAN 71: A__UHD Cores
    • VLAN 81: Power Cores
    • VLAN 91: A__line devices
    • VLAN 101: Workspaces
    • VLAN 111: Timing & synchronisation

• A VLAN per location/application
  • This method subnets the IP address range assigned to the Broadcast Control / Management fabric and creates networks and VLANs based on the devices that are grouped by their application or location — e.g.
    • VLAN 11: Studio A (audio): A__UHD Cores, XCS servers, A__line devices, mc² consoles

Customers can also choose to use elements of both approaches in their designs. 

Example LVN IPAM Structure

For customers new to IP in general, Lawo can provide IPAM guidelines which enable customers to:

• Plan for growth at the start of their IP journey
• Optimize IP address allocation
• Ensure unique IP ranges are allocated to each facility
• Ensure unique IP ranges are allocated to each fabric
• Ensure unique IP ranges are allocated to each endpoint
• Enable facility-to-facility connectivity and communication
• Accommodate from small to large facilities
• Provide consistent IPAM information making documentation easier to maintain
• Easily implement network security features  

Example LVN Fabrics

The LVN IPAM structure example implements the following fabrics:

Example LVN Unicast Address Ranges

Customers are advised to allocate a unique IP address range to each IP broadcast facility themselves. In this example, the customer has chosen 10.1.0.0/16:

The 10.1.0.0/16 IP address range can then be subnetted into smaller IP ranges and assigned to the fabrics.

Example LVN Multicast Address Ranges

Lawo advises customers to use the 'Administratively Scoped' (private) multicast address range 239.0.0.0 - 239.255.255.255. This range is equivalent to the unicast private IPs (RFC 1918) previously mentioned and is used for local multicast within an organization. The range can be subnetted into two equal ranges and provides over 8.3 million multicast addresses to each Streaming Media fabric:

Customers can also choose to make distinguishing between the Red and Blue streaming media networks easier by changing the starting point of the second octet, for example:

Multicast Aliasing

In an Ethernet network, multicast IP addresses (224.0.0.0 to 239.255.255.255) need to be mapped to MAC addresses so that network devices can properly forward packets at Layer 2. IPv4 multicast addresses are mapped to MAC addresses in the following way:

• The first 25 bits of the multicast MAC address are fixed: 01:00:5E
• The next 23 bits of the MAC address come from the last 23 bits of the multicast IP address

Therefore, multiple different multicast IP addresses can map to the same MAC address as 23 bits of the 32-bit IP address are used. The 239.0.0.0 range assigned to the Red Streaming Media fabric has the same MAC address as the 239.128.0.0 range assigned to the Blue Streaming Media fabric, however this is not a problem because the LVN IPAM structure avoids multicast aliasing by implementing the following measures:

• Routing multicast at Layer 3 (instead of relying only on Layer 2 forwarding) ensures that IP addresses are respected rather than just MAC addresses
• Multicast routing protocols like PIM Sparse Mode (PIM-SM) prevent multicast aliasing by using explicit join requests
• The endpoints are separated by L3 boundaries e.g. /30 networks on each routed interface
• The 239.0.0.0 and 239.128.0.0 ranges are in separate fabrics

AIS Multicast Organization (audio-only)

MIS Multicast Organization

Should a customer wish to evolve a facility and integrate an SDN controller in the future, the example LVN IPAM structure for unicast and multicast above is also compatible with Arista's MCS and Cisco's NDFC/NBM SDN controllers.

Continue to Chapter 2