Stream Addressing; Multicast Group Addressing - Harris CM-30 Installation & Operation Manual

NetXpress LX & CM-30 Installation & Operation Manual
Version 1, September 2010
2.2.2

Stream Addressing

The stream addressing process involves designating a destination IP address for both unicast and
multicast IP streams (Section 4.3.5– Configure Streams). During the process of adding streams,
individual streams are designated as either unicast or multicast in the Transmission Type field (Section
4.3.5.1 – Stream Creation).
When you create a stream, a UDP port number must be specified for both the local and remote
NetXpress LX devices. The RTP protocol conversation between the two devices takes place through the
specified UDP ports.
The range for UDP port numbers must be greater than or equal to 50000 and a multiple of 5, ending
in either a 0 or a 5. For unicast and multicast receive streams, the combination of peer's IP address
and source and destination UDP ports must be unique. For multicast transmit streams, each stream
must have unique ports.
Many networks use a device known as a "firewall" at the entry point to the network to provide security
against hackers and other undesirable applications. Usually, network devices in the private network
behind the firewall can freely transmit out using any UDP port number. However, devices are blocked
from receiving packets using a UDP port number until a packet is transmitted out the firewall using the
same UDP port. When setting up the network for a NetXpress LX installation, you may need to
configure the firewall to allow communication on the UDP port numbers used for stream traffic before
attempting to bring up a stream.
2.2.3

Multicast Group Addressing

The CM-30 IP interface module, within the NetXpress LX system or an original Intraplex system,
supports multicast use for stream transmission and supports creating up to 32 transmit, receive, or a
combination of transmit and receive streams. This system does not make any restrictions on the type
of multicast address used for a stream destination. Therefore, you determine how you want the
multicast address space to be administered. Figure 2-1 represents a scenario where multicast
addresses are "administratively scoped." However, some customers may also require GLOP
assignment by the carrier WAN, using address ranges 233.x.x.x, and the NetXpress LX system can
accommodate that addressing scheme as well. Section 4.3.5.1 – Stream Creation gives additional
information regarding multicast addresses.
2-4
2 – Functional Design
Harris Corporation
Intraplex Products