Telos Zephyr Xstream User Manual page 330

STREAMING MODES
Depending on the Interface selected in the TEL menu, the Xstreams streaming works differently.
Here is a review of the different options:
HTTP
The familiar Pull‐Only HTTP remains, however we strongly recommend the use
of one of the following RTP based options. The Zephyr is still a server only, not a
client. HTTP streaming is used primarily with desktop players (Audioactive
Player, WinAmp, etc.) for confidence audio. It is not to be used on the public
internet due to limitations in the Zephyr's TCP stack. If long‐range/long‐term
HTTP streaming is required, a Shoutcast Server (or other stream replicator) can
be used as a client.
RTP/UDP
Real‐Time Protocol streams are Push‐only. One server can send to several
clients, who decode the audio if they are also in RTP streaming mode. RTP is a
transport protocol, not a connection protocol, which is why it works in this way.
The "connection protocol" is the user hitting the Dial button.
SIP
Unlike RTP, SIP is a connection protocol, not a transport protocol. SIP
negotiates a bi‐directional connection between the two units, behaving much
like a telephone or ISDN call. Progress is related to the far side as well as the
local user. The far end unit may be reported as busy (unlike RTP, which sends
regardless of the readiness of the receiver), etc.
SIP uses RTP as its transport protocol. What this means, basically, is that SIP
negotiates for each side of the connection to send an RTP, push‐only stream to
the other side. The result is a bi‐directional connection.
PORTS (IP PORT)
Each IP device must have an IP address. However, each IP address can handle
multiple connections, using different ports. Sort of like different extensions on
the same office telephone system.
IP ports to be used by the streaming system are listed on the Telco configuration
page in all modes.
USER'S MANUAL
Appendix 6 – Special Operational Modes 318