Specifications

Installation and Operation Manual Chapter 1 Introduction
Vmux-210 Ver. 1.1 Functional Description 1-13
For more information about VLAN tagging, see IEEE Std 802.1D&Q.
E1/T1/Serial Main Link
The E1/T1/Serial main links receive Ethernet frames from the CPU and forward
them to the remote device over a TDM network or a leased line.
The E1/T1/Serial Links normally transmit the HDLC data transparently. However, a
special mode to support applications opposite certain Cisco-manufactured
equipment is provided. This mode uses a Cisco HDLC header format.
Ethernet Main Link (ETH NET Port)
The 10/100BaseT main link receives Ethernet frames from the CPU via the
Ethernet switch and forwards them to the remote device over the IP network.
The 10/100BaseT main link supports full duplex transmission with
autonegotiation and half duplex with the backpressure option.
Ethernet User LAN (ETH USER Port)
The 10/100BaseT user LAN port receives Ethernet frames from the user's LAN via
the internal Ethernet switch and forwards them to the remote device over the
main link. This port supports full duplex transmission with autonegotiation and
half duplex with the backpressure option.
Rate Limiting on Ethernet ports
To solve the problem of transferring voice as well as 10/100 Mbps Ethernet data
over a TDM/Serial uplink with small bandwidth (for example, 256 kbps), the
ingress data rate on either Ethernet ports can be limited to one of several values
between 128 kbps and 8 Mbps, plus fragmentation of the packets.
Integral Ethernet Switch
All traffic between the voice ports, the Ethernet ports and the Serial Link is
routed through the Vmux-210’s built-in Ethernet switch. This switch provides the
capability for VLAN tagging of the various traffic, as well as the capability for
discarding unrecognized traffic.
VLAN Tagging on Ethernet and E1/T1/Serial Ports
The VLAN tagging feature enables adding a VLAN tag to the traffic coming out of
a certain port, in order to identify its source, as well as offering the ability to
remove the VLAN tag from all traffic coming out of a certain port. In addition, a
“Double Tagging” mode is available to always add a tag to packets, even if one
already exists. The VLAN ID and priority level of the added tag are given according
to the port from which the packet
entered (ingress) the integral Ethernet switch.
For untagged packets, or packets tagged with an unrecognized ID, two possible
security policies can be set per port: ON (broadcast all) or OFF (discard all).