TANDBERG D13841.01 - Manual (Page 11)

1 Introduction
11
Red Alarm or Loss of signal (LOS) indicates that there is no signal and thus no framing info
received. The same effect will be obtained by pulling out the PRI cable. This may also be caused
by a broken connector in the receive (RX) part of the cable.
Yellow Alarm or Remote Alarm Indicator (RAI) means that the 3G Gateway is receiving framing
info, but in this framing info the other side tells the 3G Gateway that it is not reading the
gateway
’
s transmitted framing info. Typically, this may be a broken connector in the transmit (TX)
part of the PRI cable. This could also indicate weak or noisy signal in the transmit (TX) part of the
PRI cable.
Blue Alarm indicates that the received frames are not synchronized properly.
No LED
’
s lite indicates that layer one framing is working (right protocol like for example EURO
ISDN selected), but that however there is a problem at layer 2 caused by for example a CRC4
configuration mismatch.
1.1.1 3G GATEWAY Capacity
–
typical scenarios
Due to the fixed bandwidth of UMTS video telephony every call will be limited to 64 kbit. This
offers a capacity of 30 simultaneous calls through a single PRI 3G Gateway or 8 calls through a 4
x BRI 3G Gateway. Due to audio transcoding (AMR to G.711) the bandwidth at IP side is 109
kbit/s per session, 64 Kbit G.711 audio and 45 kbit H.263 video. Depending on the option
package and version of the 3G Gateway (PRI or BRI) the amount of simultaneous 3G calls can
be less then 30 or 23 for T1.
.