RAD Data comm Vmux-2100 Voice Trunking Gateway Configuring Keep-Alive Suppression Rate

Vmux-2100Installation and Operation Manual Chapter 4 Management from a Terminal

6.In the signaling table, select a signaling bit that you want to configure by pressing <Tab>.

7.Configure the signaling bit by typing a number corresponding to the desired value (see Table 4-1), and pressing <Enter>.

Table 4-1. Signaling Bits Configuration

Parameter	Description	Value
A, B, C, D Bit	Selects which incoming bit	0	– Transmits zero
	(from the remote side) to	1	– Transmits one
	transmit on the A bit toward	A – Transmits the incoming A bit
	the Vmux-2100’s local PBX.
		B – Transmits the incoming B bit
		C – Transmits the incoming C bit
		D – Transmits the incoming D bit
		NOT A – Inverts the incoming A bit and transmits it
		NOT B – Inverts the incoming B bit and transmits it
		NOT C – Inverts the incoming C bit and transmits it
		NOT D – Inverts the incoming D bit and transmits it
IDLE SIGNAL	Selects the code transmitted	0	– Transmits zero
	on A, B, C, and D bit when the	1	– Transmits one
	channel is idle
OOS SIGNAL	Selects the code transmitted	0	– Transmits zero
	on A, B, C, and D bit when the	1	– Transmits one
	channel is out of service

Configuring Keep-Alive Suppression Rate

When Vmux-2100 with CCS signaling is connected to the PBXs operating with the SS7 signaling, the PBXs use one timeslot to transmit signaling information. The signaling information is passed over the signaling link in the form of the following signal units:

•Message signal units (MSUs) provide all signaling associated with call setup and tear down, database query and response, and SS7 network management.

•Link status signal units (LSSUs) provide information on the link status between the network nodes (initiation of link alignment, quality of the signaling traffic etc).

•Fill-in signal units (FISUs) carry no information payload. They occupy the link, when there are no MSUs or LSSUs to send. FISUs are also referred to as “keep-alive” messages.

Often, in the absence of signaling traffic, the signaling links become flooded with the FISUs, causing communication disruptions. In order to prevent this, you can enforce Vmux-2100 to drop certain amount of FISUs (up to 90%). You can also disable the FISU dropping by configuring the keep-alive suppression rate to 0%. It is necessary, when working with non-SS7 CCS signaling (for example ISDN), or if the FISUs are used to acknowledge the receipt of the signaling messages. In the latter case, system performance may become unsatisfactory.

Configuring the Vmux-2100 System 4-15