Comtech EF Data CDM-625A Installation And Operation Manual page 549

CDM-625A Advanced Satellite Modem
Appendix D
Note that other fields supported in the MCED-100 are not included.
The entire CID message is broken into 18 packets containing 122 bits (formatting, FEC and user
information) for a total message length of 2,196 bits for the transmission of the MetaCarrier.
Each packet of the MetaCarrier message carries 32 bits of CID information data. However, the
MAC address is sent at a higher rate (more often), so that upon reception of a frame that is
comprised of three (3) packets, the MAC address may be obtained.
The data rate of messages being carried in the MetaCarrier is shown before spreading is applied
and the associated time to send a complete CID message (including the framing and FEC). The
time for a complete message is only valid once the MCDD-100 has achieved lock to the
MetaCarrier that may cause the stated times to be longer:
Therefore, the time for the CDM-625A with MetaCarrier to insert a complete CID ID sequence is
as follows. Note that the time for unique ID may be shorter than shown, since upon achieving
lock to the MetaCarrier, the unique ID is made available immediately since MetaCarrier lock
requires the reception of three full packets to declare lock.
Embedded
MetaCarrier rate
224 kcps
112 kcps
56 kcps
28 kcps
14 kcps
D.4 Configuring the CDM-625A for Carrier ID Operation
Carrier ID operation requires that you first enable Carrier ID feature operation, and then create
a MetaCarrier Custom Message. All other parameters (center frequency, symbol rate, and the
CDM-625's MAC address) are set automatically. The CDM-625A provides several means for
configuring Carrier ID operation:
•
Local Control via the CDM-625A Front Panel keypad and VFD.
•
Remote Control with a user-supplied PC via the
o CDM-625A Web Server (HTTP) Interface using a compatible Web browser.
o Serial-based or Telnet-based Remote Control Interface using a terminal
o Ethernet-based Simple Network Management Protocol (SNMP) using a Network
CID Data Rate
56 bps
28 bps
14 bps
7 bps
3.5 bps
emulation program or Windows Command-line.
Management System (NMS) and Management Information Base (MIB) File
Browser.
Time for Complete
Message
41 seconds
82 seconds
164 seconds
328 seconds
656 seconds
D–3
Revision 0
MN-CDM625A
Time for Unique ID
6.9 seconds
13.8 seconds
27.6 seconds
55.2 seconds
110.4 seconds