Terms Defined

1
SONET

• Terms Defined
• SONET is a method (not a network) of providing a
  high-speed, low error-rate, international,
  fiber-optic multiplexed transmission standard for
  interface between the PTTs, IXCs, and LECs.
• It also provides a technology that allows the
  major IXCs and PTTs to internationally
  standardize and control broadband network
  transport media through a common fiber interface
  called a midspan meet.
• Vendors and service providers consider SONET a
  common interconnectivity medium for direct fiber
  services such as SMDS and ATM

2
SONET

• SONET uses both synchronous and asynchronous
  transfer modes through the use of a fixed
  data-transfer frame format including user data,
  management, maintenance, and overhead.
• STANDARDS
• SONET standards have been introduced in three
  phases
• Phase I Hardware specifications
• Phase II multiple vendor connectivity and
  management
• Phase III builds upon Phase II providing
  additional network management, performance
  monitoring, and control functions.

3
SONET

• SONET STRUCTURE
• The SONET Optical Carrier (OC-N) structure
  consists of OC-N levels multiplexed to form
  higher-speed transport circuits that range into
  the gigabits range and provide an alternative to
  aggregating multiple DS1 and DS3 transmission
  facilities
• The basic structure of SONET is built around
  Synchronous Transport Signal level 1 (STS-1)
  transport through an Optical Carrier (OC-N)
  signal over fiber optics.
• An aggregate 51,84 Mbps STS-1 bit stream, when
  converted from electrical to fiber optic is
  called Optical Carrier-1 (OC-1)
• It is composed of a transmission of 810-byte
  frames sent at a rate of 8000 times per second.

4
SONET

• SONET STRUCTURE (Continue)
• Current SONET speeds range from 51.84 Mbps (OC-1)
  to 9.95328 Gbps (OC-192)
• Any subrate signals below OC-1 are multiplexed to
  form a single OC-1 channel.
• Refer to Table 15.1 (p. 597)
• Refer to Table 15.2 (p. 597)

5
SONET

• Multiplexing
• SONET provides direct multiplexing of both SONET
  speeds and current asynchronous and synchronous
  services into the STS-N payload.
• Payload types range from DS1 and DS3 to OC-3c and
  OC-12c ATM and SDH/PDH payloads.
• Refer to Figure 15.1 (p.598)
• Other major advantage of SONET is that each
  individual signal down to the DS1 level can be
  accessed without the need to demultiplex and
  remultiplex the entire OC-N level signal.
• This is commonly accomplished through a SONET
  Digital Cross-Connect (DXC)

6
SONET

• Multiplexing (Continue)
• It is important to note that SONET multiplexing
  requires an extremely stable clocking source with
  a stable reference point.
• Thus, the frequency of every clock within the
  network must be the same or synchronous with one
  another.
• This central clocking source must be at least a
  Stratum level 3 source, with a Stratum 1
  preferred for greatest accuracy.

7
SONET

• SONET Architecture Layers
• There are four layers to the SONET architecture
• physical defines the physcial fiber type, path,
  and characteristics
• section builds the SONET frames from either
  lower SONET interfaces or electrical interfaces
• line provides synchronization, channel
  multiplexing, and protection switching.
• path manages the actual data transport across
  the SONET network, as well as the pointer
  function
• Refer to Figure 15.2 (p. 599)
• Refer to Figure 15.3 (p. 600)

8
SONET

• OC-N Midspan Fiber Meet
• The OC-N midspan fiber meet allows CPE, LEC, and
  IXC hardware from different vendors to interface
  with each other via SONET.
• It provides a single platform base for access
  from the central office to the CPE
• Refer to Figure 15.5 (p. 601)

9
SONET

• Data communications Channels (DCC)
• SONET transmissions also contain communications
  channels which transmit network management
  information between network elements.
• This information includes alarm, control,
  maintenance, and general monitoring status.
• Each SONET terminal and regenerator uses a 192
  kbps channel, and each optical line between
  terminal multiplexers uses a 576 kbps channel for
  the DDC

10
SONET

• Frame Format and OAM Elements
• SONET frame payloads are not synchronized by a
  common clock even though SONET is a synchronous
  technology.
• The standard SONET frame has two major pieces -
  payload and overhead - functional in Phase I
  implementations.
• Refer to Figure 15.6
• Payload
• The payload is defined as the actual data to be
  transported across the SONET path.
• Payloads can vary depending on the OC speed of
  transport.

11
SONET

• Payload (continue)
• Payloads can take many forms, such as typical
  T-carrier channels (e.g., DS3), FDDI, SMDS, ATM,
  or Virtual Tributaries (VTs) of various sizes.
• Payloads are backward compatible with the North
  American, European, and Pacific Rim standard
  transport technologies (DS and CEPT)
• The payload envelope of the frame can vary in
  size in 774-byte increments, and the term used
  for the envelope is Synchronous Payload Envelope
  (SPE)
• SONET uses pointers to provide synchronization
  to avoid having timing and slipping problems

12
SONET

• Virtual Tributary
• Virtual tributaries are the building blocks of
  the CPE.
• The label VTxx designates virtual tributaries of
  xx Mbps.
• These virtual tributaries are labeled as VT1.5
  for DS1, VT3 for DS1C (3 Mbps), VT2 for CEPT E1,
  and VT6 for DS2 (6 Mbps).
• Refer to Table 15.3 (p. 607)
• VTs are combined to form VT groups. These VT
  groups consist exclusively of three VT1.5s, four
  VT2s, two VT3s, or one VT6 within a 9-row by
  12-column portion of the SPE

13
SONET

• Virtual Tributary (continue)
• VTs can either operate in
• locked mode - fixes the VT structure within an
  STS-1 and is designated for channelized operation
• floating mode - allows these values to be
  changed by cross-connects and switches and is
  designated for unchannelized operation.
• The common tributary is VT1.5, which supports a
  virtual tributary of 1.5 Mbps through a DS1
  transport envelope.
• VTs run from the VT1.5 through a VT6 (DS2)
• Refer to Table 15.4 (p. 608)

14
SONET

• Synchronization and Pointers
• pointers are used by SONET devices to easily
  identify subchannels down to the DS0 level within
  a SONET transmission.
• These pointers are located within the line
  overhead portion of each frame.
• Refer to Figure 15.12 (p. 609)
• pointers are lso used to identify virtual
  tributaires (VTs) within an SPE

15
SONET

• Overhead and the Control Field
• The SONET overhead structure parallels the
  existing telephone network, with three layers to
  match section, line, and path segments.
• Refer to Figure 15.13 (p. 609)
• Bit Interleave Parity Check (BIP-8)
• Parity is provided through a 1-byte Bit
  Interleave Parity (BIP-8) code at each section,
  line and path segment of the frame.
• The section BIP assures error-free transport
  between regenerators,
• The line BIP assures error-free transport between
  terminating devices
• The path BIP assures error-free transport between
  line termination equipment.

16
SONET

• Bit Stuffing
• When the incoming tributary data rates cannot
  fully meet the STS-N rate, the SONET device
  performs bit stuffing to achieve the desired
  badnwidth.
• This is as simple as inserting extra bits into
  the data stream, which are then stripped off at
  the destination SONET device.
• Bit stuffing is also used for frame
  synchronization. This technique is used when the
  access hardware and network hardware are using
  different timing sources having clock frequency
  differences.

17
SONET

• OAM Structure
• The Operations, Administration, and Maintenance
  (OAM) functions of SONET are divided into three
  levels
• F1 defines OAM flows between regenerator
  sections and between regenerators and LTE
• F2 defines OAM flows between LTEs at the
  termination of section end points.
• F3 defines OAM flows between PTE elements that
  perform payload assembly and disassembly, error
  check operations, and cell delineation over the
  transmission path.

18
SONET

• SONET Hardware
• The most common equipment term used is the SONET
  terminal.
• The word terminal, or terminal adapter, is used
  at times to represent a SONET multiplexer, DXC,
  and even a switch.
• OC-N -to-OC-N SONET devices, those that provide
  the interface of OC-12 and OC-48 speeds to
  higher-speed tributaries like OC-192, are most
  often called terminals as well.
• The primary benefit of SONET Central Office (CO)
  terminal equipment - terminals, multiplexers,
  terminal multiplexers, DXCs, and switches - is
  the reduction of equipment required for DS1, DS3,
  and OC-N connectivity and interswitch trunking.

19
SONET

• SONET Terminating Multiplexers
• Terminating multiplexers provide user access to
  the SONET network
• Terminating multiplexers, also called PTE, turn
  electrical interfaces into optical signals by
  multiplexing multiple DS1, DS1C, DS2, DS3, or E1
  VTs into the STS-N signals required for OC-N
  transport.
• These devices are configured in point-to-point
  configurations. The most common is the
  point-to-point, four-fiber configuration over the
  line, where two fibers are connected between
  two terminals
• Refer to Figure 15.16 (p. 614)

20
SONET

• SONET Terminating Multiplexers
• SONET terminals are typically connected in fiber
  rings, with each device connected to another
  through a two-pair fiber configuration.
• Refer to Figure 15.17 (p. 614)
• For SONET transmission LTE terminal adapters are
  also used which interface up to 84 DS1s into a
  single OC-3 interface
• Refer to Figure 15.18 (p. 615)

21
SONET

• SONET Concentrators
• SONET concentrators operate the same way as
  electrical concentrators and hubs, concentrating
  OC-3, OC-12, and OC-48 interfaces into
  higher-transmission rates like OC-192.
• SONET Add/Drop Multiplexer (SADM)
• SONET add/drop multiplexers allow the provider to
  drop and add not only the lower SONET rates, but
  also electrical interface rates down to the DS1
  level.
• Drop-and-insert, drop-and-continue, and broadcast
  mode are standard features.
• Refer to Figure 15.19 (p. 616)

22
SONET

• SONET Digital Loop Carrier Systems (DLCs)
• Digital Loop Carrier systems (DLCs) are used to
  concentrate multiple DS0 traffic from remote
  terminals into a single OC-3 signal.
• These devices are typically situated at the LEC
  and handle both voice and data traffic, providing
  an interface for non-SONET CPE, LEC, and CO
  switches to the SONET public network.\
• DLCs have many capabilities and can handle access
  for many of the data services such as N-ISDN and
  B-ISDN

23
SONET

• SONET Digital Cross-Connects (SDXCs)
• SDXCs allow switching and circuit grooming across
  all levels fo the transmission down to the DS1
  level, including those that interface to the SDXC
  without being on the incoming or outgoing
  transmission.
• SDXCs provide SONET OC-N level cross-connect
  provisioning capabilities and can also act as a
  SONET hub to provide both asynchronous and
  synchronous user or network access.

24
SONET

• SONET Digital Cross-Connects (SDXCs) (Continue..)
• SONET DXCs use pointers rather than traditional
  DXC slip buffers to mark the beginning of a DS1
  frame and allow insertion/extraction with minimal
  delay.
• The additional SDXC features include
• Network monitoring and testing
• Network provisioning
• Maintenance
• Network restoration
• Refer to Figure 15.20 (p. 618)

25
SONET

• SONET Digital Cross-Connects (SDXCs) (Continue..)
• SDXCs come into two types
• Wideband (WDXC) lower-speed device which
  provides cross-connect capability for floating
  VTs within an STS-N
• Broadband (BDXC) higher-speed device which can
  both cross-connect at DS3 (asynchronous or
  synchronous) and STS-1 signals and provide
  concatenation of multiple STS-1 signals to STS-N
  levels

26
SONET

• SONET Broadband Switches
• SONET broadband switches provide the switching
  capability found in major voice switches, but
  operate at the higher OC-N levels.
• Many SONET terminal and switch vendors are now
  including SDXC capabilities within their
  switches.
• A need also exists for this functionality in the
  CPE environment interfacing many LAN and MAN
  technologies.
• Refer to Figure 15.23 (p. 620)

27
SONET

• SONET Regenerators and Optical Amplifiers
• Regenerators reshape and boost signals that have
  incurred dispersion or attenuation over long
  transmission distances.
• SONET Equipment Vendors
• SONET hardware terminal vendors can be separated
  into three categories
• category 1 vendors pushing the SONET DXC
• category 2 vendors offer drop-and-insert
  multiplexer products.
• Category 3 vendors advocate integrated SONET
  message switches.
• Most systems today are being installed at OC-48
  speeds, with some deployment of OC-192 systems,
  and are all new hardware devices.

28
SONET

• Interfaces
• The Network-Node Interface (NNI) specifies the
  link between existing in-place digital
  transmission facilities and the SONET network
  node, as well as the process for converting the
  electrical signal into optical pulses for network
  transmission.
• This is the primary interface from the electronic
  world into the optical world.
• There are three major SONET interface options
• Direct CPE or CO hardware interface
• Gateway device to convert to OC levels
• Conversion within the SONET switch itself

29
SONET

• Services Support
• Typical services to ride over SONET networks
  include
• Digital Data Service (DDS)
• N-ISDN
• ATM
• X.25/X.75
• Frame Relay
• FDDI/FDDI-II
• 802.6/SMDS
• With SONET, users will be able to dial up
  whatever bandwidth increments are needed.

30
Cisco

• Configuring the Catalyst 1900 Switch

31
Objectives

• Configure the Catalyst 1900 Switch CLI
• Configure the Catalyst 1900 Switch Hostname and
  Passwords
• Configure the Catalyst 1900 Switch Security
• Configure Virtual LANs
• Configure ISL Routing

32
Features of the 1900 Switch

• Types of Operating Systems
• IOS-based
• Set-based
• The Three Configuration Options
• Command Line Interface (CLI)
• Visual Switch Manager (VSM)
• Original Menu System
• Menu-based options

33
Catalyst 1900 Switch
34
Cisco 1900 IOS Configuration Commands

• Set the passwords
• Set the hostname
• Configure the IP address and subnet mask
• Identify the interfaces
• Set a description on the interfaces
• Define the duplex of a port
• Verify the configuration

35
IOS Commands (cont.)

• Setting the Passwords
• Setting the User Mode and Enable Mode Passwords
• Setting the Enable Secret Password

36
IOS Commands (cont.)

• Setting the Hostname
• Setting IP Information
• Configuring Switch Interfaces
• 10BaseT Interfaces
• FastEthernet Interfaces
• Setting Descriptions
• Viewing Descriptions

37
IOS Commands (cont.)

• Configuring the Port Duplex
• Options
• Verifying IP Connectivity
• Erasing the Switch Configuration
• Managing the MAC Address Table
• Setting Permanent MAC Address Entries
• Setting Static MAC Address Entries

38
IOS Commands (cont.)

• Configuring Port Security
• Using the Show Version command
• Changing the LAN Switch Type

39
Configuring VLANs

• Example
• gten
• config t
• Enter configuration commands, one per line. End
  with
• CNTL/Z
• (config)hostname 1900EN
• 1900EN(config)vlan 2 name sales
• 1900En(config)vlan 3 name marketing
• 1900En(config)vlan 4 name mis
• 1900EN(config)exit

40
Configuring VLANs

• Assigning Switch Ports to VLANs
• Configuring Trunk Ports
• Clearing VLANs from Trunk Ports
• Verifying Trunk Ports
• Configuring ISL Routing

41
Configuring VTP

• Configuring the Domain
• Adding to a VTP Domain
• VTP Pruning

42
Restoring or Upgrading the Catalyst 1900 IOS

• Command
• copy tftp//tftp_host_address/IOS_filename opcode
• Backing Up and Restoring the Catalyst 1900
  Configuration

43
CDP with the 1900 Switch

• Commands
• sh cdp
• cdp timer
• cdp holdtime

44
Summary

• Configured the Catalyst 1900 Switch CLI
• Configured the Catalyst 1900 Switch Hostname and
  Passwords
• Configured the Catalyst 1900 Switch Security
• Configured Virtual LANs
• Configured ISL Routing