This presentation provided by Bob Klessig of 3COM Corporation.
bob_klessig@3mail.3com.com

Service Description of SMDS

. Basic Concepts
. Feature Descriptions
. Economics
. ATM

SMDS Paradigm
SMDS is not a MAN

* Device conforming to IEEE Std. 802.6 - 1990 can attach to the Service Interface and access SMDS
* For single CPE configurations, only a subset of IEEE Std. 802.6 - 1990 is required
* No distance limitation

SMDS as a Subnetwork for IP

* See RFC 1209

SMDS Packet (simplified)

* Address Fields

- 4 bit type field followed by 60 bits of address
- Address up to 15 BCD digits (60 bits)
- E.164 (telephone number)

* Destination Address types

- Individual or Group (multicast) address

* Source Address type

- Individual only
- Up to 16 individual addresses can be assigned to a service interface

Connectionless Service

* No connection establishment required to start exchanging data
* Packet delivered unchanged

Group Addressing

* Group membership not required to send to group
* Group address delivered to destinations

Source Address Validation

* Source Address must be one assigned to service interface
* Prevents spoofing
* Usage charging integrity

Address Screening

* B is a "private" address

- A, B, D, and E form a logical private network

* H is a public "address"

Access Classes for DS3 Interfaces

* Defined by a credit manager
* Packets that exceed available credit are discarded

- Predicable behavior
- Access class violations can be monitored by Customer Network Management

* Resulting network economies will be shared with the customer

Access Class Values
Customer Network Management
SMDS Economics - 1
SMDS Economics - 2
SMDS Economics - 3
Providing SMDS with ATM
Summary

* SMDS is designed to work with existing LAN interconnection architectures
* Features are designed to exploit public switched capability
* Customer Network Management is based on SNMP
* SMDS provides public switched economics
* SMDS will transition smoothly to ATM/BISDN