NCast Telepresenter M4 - Manual (Page 48)

NCast Telepresenter Reference Manual
Sample Rate Channels Bit Rate Quality
11 kHz. Mono 16 kbps. Phone
22 kHz. Mono 32 kbps. FM radio
44 kHz. Mono 64 kbps. CD
44 kHz. Stereo 128 kbps. Stereo CD
If audio is not to be transmitted or recorded, it may be disabled here as well.
If recording in Mono and using the Line input, make sure that active audio is available on the LEFT channel.
4.2.12. Audio MTU
The Maximum Transmission Unit (MTU) is the maximum length of a packet and is normally set to 1500. For
some special circuits (satellite links, others) the maximum size may need to be adjusted downward to avoid
packet fragmentation, which leads to inefficiencies and possible packet loss.
When using N-Way bridging, this value should be set to 1476.
4.2.13. Time-to-Live (TTL)
The time-to-live defines the number of router hops that will be valid for a packet. When the number of hops is
exceeded, the packet is discarded. The minimum value for this field is 1, and a value of 127 or greater
should be used for global transmission.
In some multicast networks TTL defines the “scope” or boundary conditions for containment of the multicast
traffic flow. The following table lists commonly accepted values of TTL used in this manner.
TTL Scope
0 Restricted to the same host. Won't be output by any interface.
1 Restricted to the same subnet. Won't be forwarded by a router.
<32 Restricted to the same site, organization or department.
<64 Restricted to the same region.
<128 Restricted to the same continent.
<255 Unrestricted in scope. Global.
TTL scopes, however, have fallen into disfavor, and current practice recommends use of administratively
scoped addresses for containment of multicast traffic flows.
4.2.14. Automatic Unicast
This Channel Type enables automatic transfer of a Telepresenter’s SDP file to a streaming server (e.g. a
QTSS/DSS server). The transfer is accomplished by RTSP ANNOUNCE commands sent from a
Telepresenter RTSP client to the server. The system makes sure that the latest version of the SDP file is
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