Overview of Advanced
Protocols and Services for
High Performance Networks
Dae Young Kim
Chungnam Nat’l Univ.
( http://ccl.chungnam.ac.kr/~dykim)
KRNET’98
Contents
CCL
• Advanced applications
• Multicast
– PIM
– BGMP
• RM
– MTP/SO
– SRM
• QoS
– IntServ
– RSVP
– DiffServ
• IPv6 in vBNS
• MPLS
• References
2
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Advanced Applications
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Advanced Applications
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•
•
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•
•
Tele-medicine
VoD
Virtual reality(2-D & 3-D)
Tele-education
Tele-conference
Traffic information
Resource explorer
CCL
QoS
high speed
new
functionality
4
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Advanced Applications (Cont’d)
CCL
• Tele-medicine
– by Los Alamos National Laboratory (LANL)
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Advanced Applications (Cont’d)
CCL
• Virtual Reality
– by NIST
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Advanced Applications (Cont’d)
CCL
• Traffic Information
– by Connect and Microsoft team
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Multicast
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PIM - overview
CCL
• Protocol Independent Multicasting
• Independent of any particular unicast routing protocol
– So, it can use whatever native unicast routing protocol.
– Therefore, it has to maintain additional state information.
• Actually two protocols : dense-mode, sparse-mode
– Dense Mode or Sparse Mode does not imply the group size.
sparse- mode
dense- mode
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PIM - DM
CCL
• Uses RPM (Reverse Path
Multicast) like DVMRP :
flood & prune
• PIM-DM routers are capable
of caching the Prune message.
• No periodic joins & no RP
(Rendezvous Point)
source
TRAFFIC
PRUNE
group member
10
group member
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PIM - SM
CCL
• Uses explicit & periodic
Join/Prune message
• DR sends periodic Join/Prune
messages to a group-specific
RP(Rendezvous Point).
• Obtaining RP information
– All routers within a PIM domain
: collect Bootstrap message.
– Routers use a set of available RPs
: distributed in Bootstrap message.
Source
RP
RP
Join
Join
DR
group member
11
Join
DR
group member
DR
group member
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PIM-SM (cont’d)
CCL
• PIM-SM routers can switch
from shared tree to shortest
path tree.
Source
– when data packets received
> threshold
RP
Prune
Join
RP
Join
Prune
DR
group member
12
DR
DR
group member
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BGMP (Border Gateway Multicast Protocol)
CCL
• Builds shared trees for active multicast groups
• BGMP uses TCP.
• BGMP messages
– Join/Prune Updates message
– KeepAlive message
– Notification message
AS #2
AS_Path : AS #3, #2, #1
Attr: Multicast
Nets: A, B, C
AS_Path : AS #2, #1
Attr: Multicast
Nets: A, B, C
AS #1
AS #3
AS_Path : AS #3,#1
Attr: Multicast
Nets: A, B, C
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AS_Path : AS #1
Attr: Multicast
Nets: A, B, C
Net A, B, C
AS_Path : AS #1
Attr: Multicast
Nets: A, B, C
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BGMP (Cont’d)
CCL
AS #2
AS_Path : AS #3, #2, #1
Prune Net C
Join Net D
AS_Path : AS #2,#1
Prune Net C
Join Net D
AS_Path : AS #1
Prune Net C
Join Net D
AS #1
AS #3
AS_Path : AS #3, #1
Prune Net C
Join Net D
Net A, B,C
AS_Path : AS #1
Prune Net C
Join Net D
AS #2
AS_Path : AS #2,#1
KeepAlive
AS_Path : AS #1
KeepAlive
AS_Path : AS #3, #2, #1
KeepAlive
AS #1
AS #3
AS_Path : AS #3, #1
KeepAlive
14
Net A, B,C
AS_Path : AS #1
KeepAlive
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Reliable Multicast(RM)
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MTP/SO (MTP/Self Organization)
CCL
• Characteristics
– receiver-initiated error recovery
– nak-based multicast
– multicast retransmission in a local group
• Coordinator
– assigning tokens & updating the message state
• Repeater
– retransmit the NAKed packet
• SO (Self Organization)
– to solve the scaling problem
– choose the best member as a local repeater (Repeater Announcement
mechanism)
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MTP/SO (Cont’d)
CCL
Coordinator
Sender
NAK
s
re t ra n
m is s i
on
Repeater
Repeater
Announcement
Member Member
Repeater
Member
Member
local group
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Repeater
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SRM (Scalable Reliable Multicast)
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•
CCL
All traffic is multicast.
Uses ALF(Application Level Framing) concept.
Receivers multicast a ‘repair request’ to ask for missing data.
Anyone can reply, not just original sender.
To avoid NAK implosion, ‘slotting & damping’ is used.
Topology-driven repair chronology
– chain topology
• by distance
• next figure
– star topology
• randomization
– tree topology
• deterministic + probabilistic
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SRM (Cont’d)
CCL
pkt #1, #2
S
pkt #2
R1
pkt #2
R2
pkt #2
R3
R4
Time
-2
snd 1,2
-1
rcv 1,2
0
rcv 2
1
rcv 2
2
snd 1?
3
rcv 1?
4
rcv 1?
5
rcv 1
rcv 2
rcv 1?
snd 1
rcv 1?
rcv 1
6
rcv 1
Chain Topology
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QoS (Quality of Service)
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Int-Serv
CCL
• Guaranteed Service
– loss-intolerant and hard real-time service
– guarantee maximum delay with no queuing loss
• Controlled-Load Service
– delay-adaptive service
– best-effort service under unloaded condition
– no specific delay & loss guarantee
• Requirements for bounded delay
– Token Bucket filter
• token rate r, bucket depth B
– WFQ (Weighted Fair Queuing)
• each flow gets its own individual queue with a share of the link
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Int-Serv (Cont’d)
CCL
• Token bucket & WFQ(Weighted Fair Queuing)
token bucket
packet of
variable- size
The bucket
holds tokens
WFQ
Router
Networks
Flow 1
One token is
added to the
bucket every T
Flow 2
Flow 3
Flow 4
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RoundRobin
service
Provides ;
. different QoS
. bounded delay
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RSVP(Resource Reservation Protocol)
CCL
• Characteristics
– adapts dynamically to changing group membership as well as to changing
routes
– not a routing protocol but depends on routing protocols
– simplex ; for unidirectional data flows
– receiver-oriented
– soft state
– reservation styles (wildcard-, shared-, fixed- filter)
• Problems
– scalability
– Can RSVP provide real resource reservation?
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RSVP (Cont’d)
CCL
• Mechanism
Sender 1
Sender 2
PATH
R
R
PATH
RESV
(merged)
R
RESV
R
R
Sender 1
RESV
Sender 1
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DiffServ
CCL
• Differentiated services to users at times traffics are
aggregated
• Elements of the DiffServ architecture
–
–
–
–
PHBs (Per Hop Behavior)
classifiers
markers
policy
DiffServ Network
Non- DiffServ
Leaf Router
Border Router
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Router operation in DiffServ Network
arriving
packet
Packet
Classifer
Packet
Marking
CCL
Packet
Forwarding
Leaf router input interface
Profile Meters
arriving
packet
Is packet
marked?
Token bucket
with policy
Packet
Forwarding
Border router input interface
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Differential Service Byte
CCL
• DS (Differential Service) byte definition
– PHB : Per Hop Behavior
– CU : currently unused
0
1
2
3
4
5
6
PHB
7
CU
DS byte
0
8
Ver.
Len.
16
TOS
identification
TTL
24
total length
flag
protocol
source IP address
fragment offset
0
8
Ver.
16
24
traffic class
flow label
payload length
next Hdr.
hop limit
checksum
source IP address
destination IP address
IPv4 header
destination IP address
IPv6 header
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DiffServ (demonstration)
CCL
• between Lawrence Berkeley & Argonne Nat’l lab
• sending two video streams over the Internet
– the priority marked stream : 8frames / sec
– the standard stream
: 1 frame /sec
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IPv6 in vBNS
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IPv6 Deployment Plans in vBNS
CCL
• Implement native (not tunneled) IPv6-over-ATM on the vBNS
backbone.
• Deploy dedicated hardware(Cisco 4700s with DS-3/ATM) for
IPv6 routing.
• Construct a full mesh of PVCs among the IPv6 routers.
• Connect to the 6bone in multiple locations via tunnels.
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vBNS IPv6 Router Deployment
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CCL
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MPLS
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MPLS (Multi-protocol Label Switching)
CCL
• As line speed & traffic volume increase
– the forwarding function can become a bottleneck
• Label Edge Router (LER)
– inserts/extract a label in the packet
– forwards the packet on a label switching/non-MPLS interface
• Label Switching Router (LSR)
– looks at the label of the packet
– swaps the label to the correct outgoing link
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MPLS (Cont’d)
CCL
• Label Distribution Protocol (LDP)
; the set of procedures & messages to inform of the mappings between labels
& streams
– Discovery Class Messages
• to announce the presence of a LSR in the network
– Adjacency Class Messages
• to establish, maintain & close down adjacencies
– Advertisement Class Messages
• to deal with advertisements of new, changes & removal
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MPLS (Cont’d)
CCL
• Label/tag switching
– referred to as Layer 2.5
Layer 2
Layer 2.5
Layer 3
Layer 4
Ethernet Header
MPLS Label
Networklayer Header
Transport-layer
Header
DATA
PPP Header
MPLS Label
Networklayer Header
Transport-layer
Header
DATA
VPI
VCI
GFC
PTI
CLP
HEC
DATA
MPLS Label
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MPLS (Cont’d)
CCL
MPLS network
non- MPLS
network
non- MPLS
network
LSR (Label Switching Router)
LER (Label Edge Router)
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References
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CCL
Quality of Serivce, paul Ferguson, Wiley, 1998
http://www.isi.edu/div7/rsvp/pub.html
http://ccl.chungnam.ac.kr/~yhkim/rsvp
RFC 2205 (RSVP, 1997)
http://diffserv.lcs.mit.edu/
A two-bit differeitiated services architecture for the Internet, “draft-nichols-diff-svc-arch-00.txt”,
Nov, 97.
Definition of the Differentiated Services Field in the IPv4 & IPv6 headers, “draft-ietf-diffservheader-00.txt”, May, 98.
The future of IP backbone technology, ERICSSON.
MPLS solutions for high capacity IP networks, ERICSSON.
Self-Organizing Multicast, “draft-bormann-som-00-pre-0.txt”, Sep, 96.
SOM, http://user.cs.tu-berlin.de/~nilss/som/som.html
Sally Floyd, “A Reliable Multicast Framework for Light-weight Sessions and Application Level
Framing”, Nov, 96.
http://www-nrg.ee.lbl.gov/floyd/srm.html
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References (Cont’d)
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CCL
RFC 1458
RFC 1700
RFC 1819
ftp://ftp.nuri.net/pub/documents/internet-drafts/draft-lim-ip-reliable-multicast-00.txt
ftp://ftp.nuri.net/pub/documents/internet-drafts/draft-kim-jtc1-sc6-ects-02.txt
http://www.ietf.org/html.charters/ngtrans-charter.html
ftp://playground.sun.com/pub/ngtrans/mail.current
MPLS architecture, draft-ietf-mpls-arch-01.txt, Sep, 98.
PIMv2-DM spec, “draft-idmr-pim-sm-specv2-00.txt”, May 21, 98
PIM-SM:protocol specification, “draft-idmr-pim-dm-spec-05.txt”, Sep 9, 97.
Dave Kosiur, ‘IP Multicasting’, John Wiley & sons, Inc.
BGMP, “draft-ietf-idmr-gum-02.txt”, Mar 12, 98.
Dave Kosiur, ‘IP Multicasting’, John Wiley & sons, Inc.
http://george.lbl.gov/BAGNet.html
http://www.ngi.gov/
http://www.canarie.ca/
http://www.internet2.edu/
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