Specifications

Installation and Operation Manual Chapter 1 Introduction
IPmux-8/16 Ver. 6.00 Functional Description 1-17
VLAN, according to IEEE 802.1p&Q, adds four bytes to the MAC layer of the
Ethernet frame. The contents of these bytes: MAC layer priority and VLAN ID, can
be set by the user. In this mode, only VLAN format frames are sent and received
by IPmux-8/16. The following figure describes the VLAN tag format.
802.1D Tag Protocol Type
(802.1QTagType)
81 00
user_priority
CFI = 0
VID
8654
1
8
1
Priority
VLAN ID
Figure 1-15. VLAN Tag Format
VLAN Groups
Every TDMoIP bundle (circuit) can be assigned a specific VLAN ID and VLAN
Priority. In addition, IPmux supports a different VLAN ID for each Manager- so that
only Managers that are included in the Manager List that transmit frames with the
correct VLAN ID, will be processed by IPmux-8/16.
Ping
IPmux-8/16 supports ping (ICMP) from the device console to any other device on
the network with a configured VLAN ID. It checks if the ping destination is one of
the configured IP destinations; otherwise is uses the default configured VLAN ID.
Packet Delay Variation
TDMoIP packets are transmitted by IPmux-8/16 at a constant rate towards the PSN
(Packet-Switched Network). Packet Delay Variation is the maximum deviation
from the nominal time the packets are expected to arrive at the far end device.
IPmux-8/16 has a jitter buffer that compensates for the deviation from the
expected packet arrival time to ensure that the TDM traffic is sent to the TDM
device at a constant rate.
The jitter buffer needs to be configured to compensate for the jitter level
introduced by the PSN. If the PSN jitter level exceeds the configured jitter buffer
size, underflow/overflow conditions occur, resulting in errors at the TDM side.
PDV
t
t
Packets Leaving IPmux-8/16
Packets Arriving
Figure 1-16. Packet Delay Variation