SMDS capabilities various geographical location and manages them in form of network with the use of telecommunication platform whenever functionality of client machine extend over WAN. It delivers service of transparent level. You can easily deployed SMDS technology using the existing equipment of customer premises. It requires minimum level of investment like lease line for data transfer. The use of dedicated lease line is helpful to reduce the issues of termination in data transfer phase.
SMDS is considered equal to ATM (asynchronous transfer mode) because it uses 53 octet cells and support 9188 packet lengths like ATM.
Functionality of SMDS Network
SMDS assists customers to establish networks with the use of customer premises equipment and LAN or WAN networks. A network of SMDS is distributed in three parts.
Dedicated connection: Dedicated line is also known as DSL line that operates at rate of 1.5 Mbps. This network includes carriers, connections and exchange links.
SMDS Protocol:
For communication between customer premises equipment and CPE and SMDS carrier, the device requires a communication protocol that is called SMDS protocol or SIP or interface protocol. Entire communication network occurs in connectionless atmosphere with the use of SNL or subscriber network interface.
The Sip is dependant on DQDB because it is a open source protocol and support features of SMDS. Different emerging technologies such as broadband ISDN is supported by with combined features of SMDS. It supports voice and video transfer on the line of ISDN.
SIP:
SMDS interface or SIP is a protocol of three level that exists on the SIP level 1, level 2 and level 3. These three SIP layers jointly control the client side network. Each layer has its own functionality and combines with other level. For example, SIP level 3 manages sending or receiving frames while SIP level 2 layer controls physical medium and SIP level 1 maintains the reliability of transmission environment.
SIP Level 1
PDU, generated at the ISP level 2 are transmitted with the use of SIP level 1. Two layers within SIP level 1 are utilized for transmission.
SIP Level:
When SIP level 3 completes the PDU processing, it transfers then to the SIP level 2 that changes them into 53 octets.
SIP Level 3:
SIP level 3 has all information ranging from 1 to 9188 in octet format and transfers all information to SIP level 2 in the right format.