AN overview of the Madge Smart Ringswitch Version 3 software.(Historical documentation) Part of the brief history to Madge Networks.

1. Smart Ringswitch
v 3.0

2. 2
Smart Ringswitch
Agenda
 Introduction
 Bridging Modes
 Connectivity
 FDDI & ATM Options
 Cut-through Operation
 Broadcast Control & VLANs
 Management & RMON
 Network Design Considerations

3. 3
Smart Ringswitch
Powerful internetworking for Token Ring
WINNERWINNER
The World’s Best
Performing Token
Ring Switch

4. 4
Smart Ringswitch
 “Cut-through” Token Ring Switch
– Source Route Bridging
– Transparent Bridging
– SRT Bridging
– SRT Plus Bridging
 4/8/12 UTP/STP/Fiber Token Ring Ports
– NODE or CONCENTRATOR mode
 ATM & FDDI Options

5. 5
Smart Ringswitch
 Port LEDs:
– Top
• GREEN = Forwarding enabled
• YELLOW = Forwarding NOT enabled
• Flashing RED = Bad ring status
– Bottom
• GREEN = NODE mode
• YELLOW = CONCENTRATOR mode
• Flashing = 4Mbps

6. 6
Smart Ringswitch
Bridging Modes
 Source Routing
 Transparent *
– Cache up to 10,000 MAC addresses
 SRT *
 SRT Plus *
– SRT with multiple rings using same ring number
– Madge proprietary
* Requires CPU v2 or later

7. 7
Smart Ringswitch
Source Routing Configuration
001 101
1
002 102
 Multiport bridge
 Virtual Internal
Ring not required
 1 bridge “hop”
 Cannot be
managed using
IBM “LAN MAN”
bridge protocol

8. 8
Smart Ringswitch
SRT Plus Bridging
 Easy ring segmentation
 Same ring number on
multiple ports
Congested
User Ring
Backbone
100
Backbone
100 100

9. 9
Smart Ringswitch
Bridging Mode Configuration
 Global Options
– Source Routing
– Transparent
– SRT+
• only if both above enabled
 Per Port Options
– Source Routing
• only if enabled globally
– Transparent
• only if enabled globally

10. 10
Smart Ringswitch
Spanning Tree Support
Switch port in
blocking mode
 All ports
support
Spanning Tree
Protocol in all
bridging modes
 Some
Ringswitch
ports may enter
blocking mode
to prevent loops

11. 11
Smart Ringswitch
Spanning Tree Support
SR
T, SRT, SRT+
SPT Frame Destin. Frame Filtering
Bridge Functional
Address
Bridge Group
Address
Spanning Tree
Explorer Frames
All Frames
SPT frames from Source Routing bridges
forwarded unchanged by Transparent bridges
TSR SR
SPT frames from Transparent bridges
blocked by Source Routing bridges
Bridging Mode(s)

12. 12
Smart Ringswitch
Port Configuration
 NODE
– connect to Token
Ring hub port
 CONCENTRATOR
– connect to Token
Ring node
– connect to Madge
SmartRAM
(access port) or
Madge Local Ring
Hub (centre port)
Hub
Switch
Switch
CCN--C-C
N-N-----
RAM/LRH

13. 13
Switch Connectivity
Token Ring Node
Token
Frame
 Token Passing
Access Protocol
 Switch port
configuration:
– NODE
MAC=0000F6000001
MAC=0000F6000002
MAC=0000F6000003
MAC=0000F6000004
CAU/CAU/
LAM/LAM/
RAM/RAM/
MAUMAU

14. 14
Smart Ringswitch
Token Ring Concentrator
Token
 Token Passing Access Protocol
 Switch port configuration:
– CONCENTRATOR
Frame
RAM/LRHRAM/LRH

15. 15
Smart Ringswitch
Dedicated Token Ring
 Transmit Immediate Access
Protocol
 Switch port configuration:
– CONCENTRATOR
– Switches connect NODE-
CONCENTRATOR
MAC=0000F6000001
MAC=0000F6000003
MAC=0000F6000002
MAC=0000F6000004
Frame
Frame
Frame
Frame

16. 16
Smart Ringswitch
Fiber Token Ring Module
Servers Servers
Ringswitch Ringswitch
SmartRAM
SmartLAM
SmartCAU
SmartLAM
SmartLAM

17. 17
Smart Ringswitch
FDDI Option
 High speed fault-tolerant backbone for switch
interconnection
 Can interconnect servers and routers
 No need for FDDI hubs
 SR, T, SRT & SRT+ modes supported

18. 18
Smart Ringswitch
FDDI Option
 Protocol Translation
– Token-Ring <> FDDI_802.2
– Token-Ring_SNAP <> FDDI_SNAP
 Protocol “Fixups”
– Converts protocol header addresses to/from FDDI
format (LSB/MSB)
– Must be enabled if PCs or routers on FDDI
backbone
– Not required if only Ringswitches
– All or none

19. 19
Smart Ringswitch
FDDI Option
Hub
Hub
Hub
FDDI Backbone
 Ringswitch interconnect
only
– no FDDI hubs required
– no protocol fixups required
Ringswitch
Dual Attached
Ringswitch
Dual Attached
Ringswitch
Dual Attached

20. 20
Smart Ringswitch
FDDI Option
Hub
Hub
Hub
 Servers & routers on FDDI
– no FDDI hubs required
– protocol fixups required
ServersRouter
FDDI Backbone
Ringswitch
Dual Attached
Ringswitch
Dual Attached
Ringswitch
Dual Attached

21. 21
Smart Ringswitch
FDDI Option
FDDI
Hubs
 Using FDDI Hubs, e.g.
Madge LANswitch
LFD-104
ServersRouter
FDDI Backbone
Ringswitch
Dual Attached
Ringswitch
Dual Attached
Ringswitch
Dual Attached
Ringswitch
Dual Attached
Ringswitch
Single Attached
Ringswitch
Dual Homed

22. 22
Smart Ringswitch
ATM Uplink
 High speed links to key network resources
 High speed links between Ringswitches
Servers
Smart Ringswitch
Collage 740
ATM Switch
Third Party
ATM Switch
Smart Ringswitch

23. 23
Smart Ringswitch
ATM Uplink
 SR, T, SRT or SRT+
Bridging Modes
ATMATM
Token Ring
ELAN
Token Rings
LES BUS
LEC

24. 24
Smart Ringswitch
ATM Uplink Configuration
 ATM
– UNI Signalling (3.0/3.1/Auto)
– SONET/SDH
– ESI
– LECS Discovery
• 1. Configured ATM Address
• 2. ILMI
• 3. Well-known Address
• 4. PVC 0/17

25. 25
Smart Ringswitch
ATM Uplink Configuration
 LEC
– ELAN name
– MAC Address
 Forwarding
– CPU-1: SR only
– CPU-2/3: SR, TB, SRT, SRT+
 Spanning Tree

26. 26
Smart Ringswitch
ATM Uplink LEC
 Bridging Mode = SR, SRT, SRT+
– LEC registers Route Descriptors when it
joins the ELAN
• Route Descriptors required for
“Specifically Routed” frames
• “Explorer” frames sent to BUS
 Bridging Mode = T, SRT, SRT+
– LEC registers as a Proxy LEC when it joins
the ELAN
• If LES can’t resolve an LE_ARP request,
LE_ARP forwarded to all Proxy LECs

27. 27
Smart Ringswitch
Redundant ATM Interface
 Default configuration:
– Primary port active
– Secondary port standby
 Port switch on physical failure
Smart RingswitchSmart Ringswitch Smart RingswitchSmart Ringswitch

28. 28
Smart Ringswitch
ATM Uplink Dual Homing
 Connections
automatically
reestablished
using alternate
route in event
of physical link
failure

29. 29
 Read only as much
of frame as required
 Output Decision on
– RIF if Source
Routing Bridge (33
bytes)
– MAC Addresses if
Transparent Bridge
(15 bytes)
Smart Ringswitch
Cut-through Process

30. 30
 Make connection
to output port
 Send frame
Smart Ringswitch
Cut-through Process

31. 31
Smart Ringswitch
Specifically Routed Frames
 Inspect Routing
Information Field to
determine output port
 “Cut Through” as fast
as possible
A
001
002
003
004
HDR DA SA RI LLC
HDR
DATA Trailer
Contro
l
001 A 003 0
Token Ring
Frame

32. 32
Smart Ringswitch
Unicast Transparent Frames
 Inspect destination
MAC address to
determine output port
 “Cut Through” as fast
as possible
HDR DA SA LLC
HDR
DATA TrailerToken Ring
Frame
0000F6123456
0000F6123456

33. 33
Smart Ringswitch
Explorer & Broadcast Frames
 Processed by Switch
CPU
– NOT “Cut Through”
– efficient broadcast
mechanism inside
switch
– Broadcast control
eliminates explorer
storms

34. 34
656566666767bytes
646463636262665544
112233
Incoming frameIncoming frame
Outgoing frameOutgoing frame
Switch buffers
Smart Ringswitch
Operation

35. 35
CRC Checking on cut-through switch
Node transmitsNode transmits
a framea frame
SwitchSwitch Node receivesNode receives
frame, doesframe, does
CRC checkCRC check No CRC check performed by
Cut-through switch
 Cannot cut-through frames
modified by switch
– source-route explorer frames
– if changing LAN access method
– if routing

36. 36
Smart Ringswitch
Latency
 Time to acquire token
– token may not be free
– may be already transmitting on output port
– Switch/bridge token access priority = 4
Standard Bridge/Router Latency
= Time to receive complete frame (20-2000 microseconds)
+ CRC check
+ Decision time
+ Time to acquire token
Madge Smart Ringswitch Latency
= Decision time (20-40 microseconds)
+ Time to acquire token

37. 37
Smart Ringswitch
Server benefits
 Response time
from remote
server similar to
local server
 Servers can be
located centrally
 Better support for
multimedia

38. 38
Smart Ringswitch
Broadcast Control
Source Route
Broadcasts
Source Route
Broadcasts IP BroadcastsIP Broadcasts IPX
Broadcasts
IPX
Broadcasts
NetBIOS
Broadcasts
NetBIOS
Broadcasts
 Eliminates
– Server congestion
– Workstation congestion
– Network congestion
Active
Broadcast
Control
VLANs

39. 39
Smart Ringswitch
Active Broadcast Control
 Workstation Ring Filtering
 All Routes Explorer Conversion
 All Routes Explorer Filtering
 IPX RIP and SAP Filtering
 IPX Type 20 Filtering
 NetBIOS Retry Control
 NetBIOS Name Caching
 IP ARP Caching

40. 40
Active Broadcast Control
Workstation Only Rings
 Configure rings as
Workstation Only or
Anything
 Block IPX and NetBIOS
broadcasts between
Workstation Only rings
101
102
103
104
W
W
W
A

41. 41
Active Broadcast Control
ARE Conversion
 Reduce broadcast traffic by
converting AREs to STEs
– Useful when protocol stack
cannot be configured for STEs
 Options:
– All
– First
– Broadcast All
– Broadcast First
“FIRST”: Only frames originating
on a directly attached ring
“BROADCAST”: Only frames to
the broadcast MAC address
(FFFFFFFFFFFF)

42. 42
Smart Ringswitch
ARE Filtering (1)
 802.1d
 Discard All-
routes
Explorer if
ANY
OUTPUT
ring number
appears in
RIF
101
102
103
104
1 2

43. 43
ARE
CACHE
TRANSMIT
RECEIVE IS THE ARE ALREADY
IN THE TABLE ?
YES
NO IS THE ROUTE SHORTER ?
NO
DISCARD BIN
YES
Smart Ringswitch
ARE Filtering (2)

44. 44
Smart Ringswitch
IPX RIP/SAP Suppression
 Switch determines
which ports are
transmitting RIP/SAP
frames
 Only forwards
RIP/SAP frames to
those ports
NO RIP/SAPs
NO RIP/SAPs
Transmits RIPs/SAPs

45. 45
Smart Ringswitch
IPX Type 20 Filtering
IPX-20
CACHE
TRANSMIT
RECEIVE IS THE IPX-20 ALREADY
IN THE TABLE ?
YES
NO IS THE ROUTE SHORTER ?
NO
DISCARD BIN
YES

46. 46
Smart Ringswitch
NetBIOS Connection Establishment
ADD_NAME_QUERY “Kirk”
DA=Netbios SA=0000F612345
0000F6123456
NetBIOS
NAME=KIRK
40000000001
NetBIOS NAME=EARTH
NAME_QUERY “EARTH”
DA=Netbios SA=0000F612345
NAME_RECOGNISED “EARTH”
DA=0000F6123456 SA=400000000001
SESSION_INITIALISE “KIRK” “EARTH”
SA=0000F6123456
NetBIOS STACKS TRANSMIT
BETWEEN 3 - 6 STE FRAMES
NetBIOS STACKS TRANSMIT
BETWEEN 6 - 10 STE FRAMES
DA=400000000001
NORMALLY 1 ARE FRAME
SPECIFICALLY ROUTED FRAME

47. 47
Smart Ringswitch
NetBIOS Filtering
 NetBIOS Name Caching
– NetBIOS names associated with specific ports
– NAME_QUERY frame only sent on appropriate port
if name in cache
– Name removed from cache if no reply seen
 NetBIOS Retry Control
– Filters excessive ADD_NAME_QUERY frames from
same station
– Configurable retry count & period

48. 48
0000F61234560000F6123456
IP 92.2.1.1IP 92.2.1.1
4000000000140000000001
92.2.1.15592.2.1.155
ARP Request
DA=FFFFFFFFFFF
SA=0000F6123456
No routing info
Port: 92.2.1.155
Port: 92.2.1.1
ARP Request
DA=FFFFFFFFFFF
SA=0000F6123456
ARE
Port: 92.2.1.155
Port: 92.2.1.1
ARP Reponse
DA=0000F6123456
SA=400000000001
SR RI=002-1-001
Port: 92.2.1.1
Port: 92.2.1.155
001001 002002
Smart Ringswitch
IP ARP Protocol

49. 49
Smart Ringswitch
IP ARP Filtering
 IP Addresses associated with specific ports
 IP ARP Request frame only sent on
appropriate port if address in cache
 Address removed from cache if not seen

50. 50
Smart Ringswitch
Virtual LANs
 Benefits
– Reduced explorer
traffic
– Prevention of
unnecessary or
unauthorised
access to servers
101
102
201
202
NetWare
Server
UNIX
Server
VLAN1
101
102
201
VLAN2
102
202
UNIX
Server
NetWare
Server

51. 51
Smart Ringswitch
Virtual LANs
 Use Switch filters to segment network
– restrict access to servers, etc
– reduce broadcast traffic
 3 types of VLAN
– Source Routing “Impermeable”
• Explorer filtering (source ring number)
– Source Routing “Permeable”
• Explorer filtering (input port ring number)
– Transparent
• Broadcast/multicast filtering (port number)
• Extra flexibility using Transparent Filter Table

52. 52
Smart Ringswitch
“Impermeable” VLAN
 Can include rings NOT connected to a switch
 Switch will NOT allow access to VLAN from
outside
002
004
A
102
104
202
203
204
B
B
B
B
VLAN

53. 53
Smart Ringswitch
“Permeable”/Transparent VLAN
 Cannot include rings NOT connected to a
switch
 Switch MAY allow access to VLAN from outside
002
004
A
102
104
202
203
204
B
B
B
B
VLAN

54. 54
Smart Ringswitch
Transparent Filter Table
 Define ports allowed to access specific MAC
address(es)
 Overrides Transparent VLAN
VLAN
Management
Station

55. 55
103
306
A
102
302
202
203
204
307
308
104
105
Smart Ringswitch
VLAN Example
 Red rings to Red server
 Green Rings to Green
Server
 105 and 306 to Black Server

56. 56
103
306
A
102
302
202
203
204
307
308
104
105
Smart Ringswitch
VLAN Example
 Permeable 102 & 202
 Permeable 302 & 204
 Impermeable 306, 105, 203,
102 & 302

57. 57
Smart Ringswitch
Management
 Protocols
– SNMP (IPX)
– SNMP (IP)
– TELNET (IP)
– Serial Terminal
 Madge TrueView
Ringswitch
Manager
– SNMP (IPX)
– SNMP (IP)
Serial
SNMP
TELNET
TrueView

58. 58
Smart Ringswitch
Management
 IP Support
– BOOTP
– DHCP
– RARP
 SNMP Support
– Authorised managers
– Trap destinations
 Microcode download
– TFTP/IP
– TFTP/IPX
– RPL/IPX

59. 59
Smart Ringswitch
RMON
Statistics
Network
Management
System
Smart Ringswitch
RMON
Probe

60. 60
Smart Ringswitch
RMON Modes
 Disable = No frames passed to RMON
 MAC Frames (recommended on all Ports)
 All Frames (recommended on 1 or 2 Ports)
 Snoop = Specific nodes
 All Frames to Address
 Mirror Port
 RMON should not be used on Full Duplex
ports

61. 61
Smart Ringswitch
Working with Large Networks
Dept Servers
Whole Company
Access
Dept Servers
 Original network

62. 62
Smart Ringswitch
Working with Large Networks
Dept Servers
Whole Company
Access
Dept Servers
 Multiple bridges replaced by switches

63. 63
Smart Ringswitch
Working with Large Networks
Dept Servers
OR
by protocol
Dept Servers
OR
by protocol
Whole Company
Access
 Single backbone relaced by several

64. 64
Smart Ringswitch
Working with Large Networks
Dept Servers
Company
Access
Dept Servers
 Hierarchical backbone network

65. 65
Smart Ringswitch
Working with Large Networks
Dept Servers
Company
Access
Dept Servers
 Hierarchical switched network

66. 66
Smart Ringswitch
Fault-tolerant Design
 Single switch
is single point
of failure
 Duplexed
switches
– Maximum
fault-
tolerance
– Doubled
bandwidth
101
102
103
104
1 2

67. S W I T C H I N G T O A T M