Specifications

Chapter 1 Introduction Installation and Operation Manual
1-8 Functional Description IPmux-24 Ver. 1.5
Service Type
This section describes the IPmux-24 operation modes, which are:
• Unframed E1/T1
• Fractional E1/T1
• Fractional E1/T1 with CAS
• HDLC.
Unframed
In the unframed mode, the incoming bit stream from each channel (regardless of
framing) is converted into IP over Ethernet frames. This option provides clear
channel end-to-end service (unframed).
Fractional
In the fractional mode, the incoming bit stream is regarded as a sequence of
N × 64 kbps timeslots (according to framing). Each predefined group of timeslots
is converted into a structure block. The structure block is packetized into IP
frames and transmitted.
This mode allows transmission of several selected timeslots without the whole E1
or T1 frame, as in transparent mode.
Fractional with CAS
In the fractional-with-CAS mode, the structure block (as described under
Fractional Operation Modes, above) also includes Channel Associated Signaling
(CAS) from timeslot 16 (E1) or robbed bit (T1). The relevant portion of the
signaling channel is packetized and sent to the destination.
HDLC
Handling HDLC in TDMoIP ensures efficient transport of CCS (common channel
signaling, such as SS7), embedded in the TDM stream or other HDLC-based
traffic, such as Frame Relay.
Timeslot Assignment in a Bundle
A pseudowire (PW) bundle is a group of timeslots associated with a specific E1 or
T1 channel. IPmux-24 places individual or multiple TDM timeslots (up to
31 timeslots for E1 or up to 24 for T1) into PWs with a single IP address
destination. IPmux-24 supports up to 64 PW bundle connections (16 bundles per
TDM link).