____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
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1 Introduction
The DS34T101/2/4/8 family of products combine E1/T1 LIUs and framers and TDM-over-packet circuit emulation
circuitry into one die. Dedicated payload-type engines are included for TDMoIP (AAL1), CESoPSN, SAToP, and
HDLC.
Products in the DS34T10x family provide the mapping/demapping capability to enable the transport of TDM data
(Nx64kbps, E1, T1, J1, E3, T3, STS-1) or other constant bit-rate data over IP, MPLS or Ethernet networks. These
products enable service providers to migrate to next generation networks while continuing to provide legacy voice,
data and leased-line services. They allow enterprises to transport voice and video over the same IP/Ethernet
network that is currently used only for LAN traffic, thereby minimizing network maintenance and operating costs.
Packet-switched networks, such as IP networks, were not designed to transport TDM data and have no inherent
clock distribution mechanism. Therefore, when transporting TDM data over packet switched networks, the TDM
demapping function needs to accurately reconstruct the TDM service clock(s). The DS34T10x devices perform this
important clock recovery task, creating recovered clocks with jitter and wander levels that conform to ITU-T
G.823/824 and G.8261, even for networks which introduce significant packet delay variation and packet loss.
The circuit emulation technology in the DS34T10x products that makes this possible is called TDM-over-Packet
(TDMoP) and complements VoIP in those cases where VoIP is not applicable or where VoIP price/performance is
not sufficient. Most importantly, TDMoP technology provides higher voice quality with lower latency than VoIP.
Unlike VoIP, TDMoP can support all applications that run over E1/T1 circuits, not just voice. TDMoP can also
provide traditional leased-line services over IP and is transparent to protocols and signaling. Because TDMoP
provides an evolutionary, as opposed to revolutionary approach, investment protection is maximized.
2 Acronyms and Glossary
Acronyms
AAL1
ATM Adaptation Layer Type 1
AAL2
ATM Adaptation Layer Type 2
ATM
Asynchronous Transfer Mode
BGA
Ball Grid Array
BW
Bandwidth
CAS
Channel Associated Signaling
CBR
Constant Bit-Rate
CCS
Common channel signaling
CE
Customer Edge
CESoP
Circuit Emulation Service over Packet
CESoPSN
Circuit Emulation Services over Packet Switched Network
CLAD
Clock Rate Adapter
CPE
Customer Premises Equipment
CSMA
Carrier Sense Multiple Access
CSMA/CD
Carrier Sense Multiple Access with Collision Detection
DS0
Digital Signal Level 0
DS1
Digital Signal Level 1
DS3
Digital Signal Level 3
HDLC
High-Level data Link Control
IEEE
Institute of Electrical and Electronics Engineers
IETF
Internet Engineering Task Force
IP
Internet Protocol
JBC
Jitter Buffer Control
IWF
Interworking Function
LAN
Local Area Network