SIP-based Mobility Management Scheme for Wireless Internet

1
SIP-based Mobility Management Scheme for Wireless
Internet

• Presenter Ashutosh Dutta
• Research Scientist,Telcordia Technologies, NJ
• adutta_at_research.telcordia.com
• (Joint work with Toshiba America Research Inc.,
  
• Toyota Info Technologies.,
• Columbia University)

2
Motivation

• Mobility and wireless are rapidly becoming the
  rule rather than exception.
• SIP is gaining acceptance as the signaling
  protocol for multimedia conferences and Internet
  telephony.
• It is essential to support wireless mobile users
  in a SIP signaling and control environment.
• Current Wireless Standard efforts using SIP
• IETF
• 3GPP (Third Generation Partnership Project)
• MWIF (Mobile Wireless Internet Forum)
• 3GPP2

3
Outline

• Objective
• Mobility Management Requirement
• Existing mobility solutions
• SIP based mobility
• Performance
• Wireless Internet Testbed Implementation
• Issues and Summary
• SIP Mobility demo

4
Why is Mobility Management Difficult ?

• Goals of mobility support in Internet
• allow a mobile device to move between different
  subnets and domains
• preserve an ongoing session between the mobile
  device and its counterpart alive while moving
• Ability to provide same service irrespective of
  network
• attachment
• Several protocols and mechanisms have been
  developed
• Broadly divided into
• Network Layer Mobility
• MIP, CIP, HAWAII, TeleMIP, MIP-LR, MIPV6
• Application Layer Mobility
• SIP based Mobility Management Scheme

5
Multimedia Protocol Stack
Media Transport
Signaling
Quality of Service
media encaps (H.261. MPEG)
MGCP
Application Daemon
H.323
SIP
RTSP
RSVP
RTCP
RTP
DNS
LDAP
TCP
UDP
CIP
MIP
ICMP
IGMP
MIP variant
Network
IPv4, IPv6, IP Multicast
Kernel
PPP
AAL3/4
AAL5
PPP
CDMA
V.34
802.11
Ethernet
Physical
SONET
ATM
6
Service Profile for all IP wireless network user
7
State of the Art Related Work
8
State of the Art Related Work
9
Related Work
10
Qualitative comparison with Mobilityapproaches
11
Objective

• To develop a mobility management scheme for
  wireless IP networks based on SIP signaling
  scheme
• Support for all types of mobility
• Support global roaming
• Independent of underlying wireless technology
• Support for real-time and non-real-time
  multimedia applications (both TCP and UDP/RTP
  based applications)
• Inter-work with todays 1G/2G telephony smoothly

12
Technical Issues for SIP Mobility
13
SIP Mobility Advantages

• Easier Interaction with associated standard IETF
  protocols
• DNS, HTTP, LDAP for location management
• SLP for service discovery
• AAA protocol (e.g.Diameter) for inter-domain
  mobility
• DHCP/DRCP for IP address configuration
• tftp for firware upload
• SDP for providing session parameters (e.g.,
  change mid-call parameters)
• RTP/UDP for transport, RTSP for stream control
  application (e.g., IP Telephony, voice mail,
  streaming)
• Elimination of triangular routing and IP-IP
  encapsulation associated with other mobility
  approaches such as MIP
• Reduces delay
• Saves network overhead
• End hosts should be equipped with SIP-UA
• Suitable for real-time multimedia traffic such as
  voice over IP and/or video streaming
• Can be used for RTP/UDP based application as is
• SIP extensions for Non-real-time application
• Complements IPV6 mobility
• Can co-exist with MIP, Cellular IP and other
  Micro-mobility approaches

14
SIP Mobility Basics

• Supports end-to-end mobility by means of
  application layer signaling
• meant for multi-media/multi-party sessions
• SIP based mobility can also be termed as
  Application Layer mobility
• More than just hand-off
• supports various types of mobility
• provides flexible services
• Compensate for lack of Mobile IP deployment
• Less reliance on underlying transport network of
  the ISPs
• Supports application-layer equivalent of Mobile
  IP registration
• Fast-handoff
• Paging

15
Types of Mobility supported by SIP

• Terminal Mobility
• Pre-session mobility (Micro/Macro/Domain)
• pre-session mobility by means of unique URI
  (ability for a user to
• be within reach under the same identifier
• while using different terminals)
• use of SIP proxy, redirect, registrar
• Hierarchical registration for faster registration
  update
• Mid-session mobility
• Move between cells, subnets, domains, supports
  handoffs
• Real-Time (RTP/UDP)
• SIP Re-invite, RTP SSRC/IP address
• Hierarchical proxy and RTP translator for fast
  hand-off within a
• domain
• Duration limited multicast between subnet handoff
• use of RTSP to control multi-media stream
• server

16
Mid-session mobility for TCP based application

• Mobility problem with TCP applications
• TCP socket - bound to source and destination
  address
• One of these addresses change gt connection
  breaks
• TCP applications ftp, telnet, web
• Application Layer restart and recovery
  capabilities
• connection close header into HTTP request
• FTP variants (e.g., bullet-proof ftp)
• Multi-homing feature of SCTP (IETF)
• TCP-Migrate Option
• SIP-eye enabled in the end-hosts - keeps track of
  the TCP end-points
• of SIP
• SIP Mobility Proxy (Columbia U.)
• an interceptor to forward data

17
Basics of SIP Mobility

• Personal Mobility
• Use of one logical address to address a single
  user located at different terminal
• One address to many potential terminals
• Many addresses reaching one terminal
• Use of forking Proxy, a user can be reached at
  any of the devices
• Service Mobility
• Allows users to maintain access to their services
  while moving or changing devices and network
  service providers
• Maintain speed dial list, address books, buddy
  lists, incoming call handling (e.g, CPL)
• As part of registration message (on a routine
  basis or upon network change) it conveys
• current network address
• Properties of the device (media supported, call
  priority etc.)
• Other configuration elements
• Session Mobility
• Allow a user to maintain an on going media
  session even while changing terminals
• Use of MGCP/Megaco
• Third-party Call control
• Refer Mechanism

18
SIP Mobility - Mobile IP
1. SIP INVITE 2. 302 client moved 3. SIP
INVITE 4. SIP OK 5. Data
SIP Pre-session Mobility
Plain Mobile IP
SIP Server
SIP Server
CH
Home Network
2
CH
3
Foreign Network
1. MN moves 2. MN re-invites 3. SIP OK 4. Data
4
MN
1
moves
MN
SIP Mid-session mobility
When both move
19
Evaluation Model for SIP and Mobile IP
Callees Home Network
High-speed link
Low-speed link
HA
MH
N hops
MIP
Callers Network
M hops
SIP
P hops
Callees Foreign Network
FA
MH
CH
20
SIP-Mobile IP Transport Delay vs. Packet size
21
Bandwidth Efficiency Gain
SIP/MIP bandwidth gain
0.6
0.5
0.4
SIP b/w efficiency
0.3
Bandwidth Efficiency
Gain
gain
0.2
0.1
0
0
100
200
300
400
500
600
Packet size in bytes
22
SIP-Based Mobilityin Military Environment
Domain 1
Domain 2
DNS
DRCP
Server
Server
Server
Re-direct Server
SIP
Mobile Node
Server
192.4.8.18
CH moves
Correspondent Host
192.4.8.20
On-going Media Session (RTP)
23
SIP mobility for Appliances
SIP for Appliances
Webphone
PocketPC
LDAP Store
Jini Controller
WML
http
SIP
OSGi GW
http
UPnP Controller
SIP
Wide-area wireless v/d Short-range LAN
I/f Location-sensitive services Personalized
services
Web Browser SIP UA
ProvisioningSystem
Location Registries(User Location)
Web server SIP User Agent Mobile Service
Logic SIP Proxy
Talisman
SIP Proxy SIP User Agent Watcher
24
SIP Mobility - Handoff -
3. Send Data to New Address
2. re-INVITE
Correspondent Host (CH)
By sending SIP re-INVITE message from new
location, CH starts sending its voice packet to
the new location and Communication continues
seamlessly
25
SIP Mobility - Handoff
Corresponding Host at
Mobile Host at
SIP signaling
IP0
IP1
RTP
Mobile Host
Invite user_at_domain Contact user_at_IP2
-gt IP2
SIP UA
SIP signaling
IP2
RTP
RAT
26
SIP Personal Mobility
Fixed Phone
Hotmail.com Server
Bob_at_hotmail.com
Bob_at_columbia.edu
Columbia.edu
Mobile Phone
7010_at_columbia.edu
Bob.Cattani_at_columbia.edu
Host
27
Session Mobility
Bob_at_mobile
Alice_at_wonderland
RTP
Bob_at_mobile
3. BYE Alice_at_Wonderland
INVITE from 2
Ongoing session
5 ACK SDP(4)
3
4
200 OK
6 ACK
200
2
1. REFER Bob_at_fixed Referred-By B1
1
Session Transferred
INVITE with no SDP
Alice_at_wonderland
2. INVITE Bob_at_fixed Referred-By B1
Bob_at_fixed
Bob_at_fixed
Session Mobility using Call transfer
Third party control
28
Registration with local SIP Registrar

• FromAlice_at_NY (1)
• Contact 193.1.1.1
• (3) CA FromAlice_at_NY (2) NY
• Registrar Contact
  AliceNY_at_CA Registrar
• FromAlice_at_NY (4)
• Contact 193.1.2.3
• Visited Network Registrar needs to map Alices
  URI to a canonical name
• Only first registration in CA needs to go all the
  way to NY
• All SIP messages to Alice need to go through SIP
  server/registrar for address translation.

29
Use of multicast for hierarchical SIP servers for
paging
searches
SIP server
TTL 256
Forwards upstream
failure
Callee has moved here
SIP server
INVITE with TTL 256
INVITE
failure
Caller
SIP server
INVITE with wider scope
TTL 64
INVITE with multicast addr.
TTL 1
30
The ITSUMO Network Architecture
Control messages (i.e..., signaling)
IDCA
Visited Network
Home Network
DCA
DCA
MS
ERC
ERC
BS
Regional IP network
Regional IP network
Internet
IP
BS
BS
Wireline IP backbone network
Radio Access Network (RAN)
Radio Access Network (RAN)
MS Mobile Station BS Base Station ERC Edge
Router Controller
31
Network Signaling and Control Architecture

IDR
Signaling
Inter-Domain Registrar
Home Network
IDCA
Visiting Network
MAAAQ
SIP Server
Home Registrar
Visiting Registrar

HR
VR

DCA
DCA
MAAAQ
MAAAQ
SIP
SIP
SIP Server
SIP Server
3G
3G
Access
Access
Regional IP network
Internet

SIP
Regional IP network

SIP
3G
MS
Access
3G
Access
Wireline IP backbone network
SIP UA in mobiles and hosts.
32
Internet Roaming (RTP Application)
Visiting Network
Home Network
Home Registrar
Visiting Registrar
SLA/SA
RTP Translator
Corresponding Host
SIP
SIP
IPch
DRCP
DRCP
ERC 1
ERC 3
Internet
207.3.232.10
BSC 1
ERC 2
BS
BSC 3
BS
BSC 2
A
128.59.11.6
207.3.232.10
BS
207.3.240.10
BS
B
D
128.59.10.6
BS
INVITE
C

• SIP UA in mobiles and hosts.

33
Supporting TCP Applications
HR
VR
Visiting Network
Home Network
Home Registrar
Visiting Registrar
MAAAQ
MAAAQ
Mobility Proxy
SIP Server
SIP Server
Corresponding Host
SIP
IPch1
SIP
Register
DHCP
DHCP
IPch
INFO
128.59.11.6
ERC 1
ERC 3
Internet
Ongoing TCP Connections
207.3.232.10
BSC 1
ERC 2
BSC 3
BS
BSC 2
A
INFO
207.3.232.10
BS
207.3.240.10
BS
B
D
BS
128.59.10.6
SIP_EYE
C
INFO

• Equip MS with SIP_EYE.

34
ITSUMO test-bed Architecture
tari.toshiba.com
Research.telcordia.com
Backbone
Border Router
Border Router
3600
3600
Media Server
SIP Server/Call Agent
SIP Server/Call Agent
Multicast Proxy
R2
R3
R1
AAA Server
SIP Server
AAA Server
DRCP Server
DRCP Server
DRCP Server
BURP
BURP
BURP
Local Server
Local Server
Ad
Local Server
Local Server
External Omni Antenna
QOS
QOS
HA/DRCP Server
QOS
QOS
VLAN Switch
VLAN Switch
VLAN Switch
VLAN Switch
External Demo
SIP UA/Mini_RGW
Micro
Macro
Domain
35
Wireless Internet Telephony Test-bed Protocols
36
Backbone
Research.telcordia.com
tari.toshiba.com
Diameter Server, visited AAA
Local SIP Server
Diameter Server Home AAA
Home SIP Server
2
1
37
NGN Application Server Environment
Telcordia NGN Application Server
API

SCE
3rd Party Application Servers
SIP
Rapid creation of new services
Softswitch
SIP
Web Server
Media Server
Gateway
IP
PSTN phone
SIP phone
End-user devices
Customer Self-Service
3rd Party SIP Application Servers
38
NGN Application Server Architecture
Information Content Tier
Application Tier
JAIN / Parlay / OSA APIs
External B/OSS and IT Backend Infrastructure
Middle Tier
SCE
Service Enabling Tier
Services

SIP
LDAP, DIAMETER,MGCP
IP Service Network
39
Initial/Example SIP-Based Voice Services

• Call Distribution / TOD routing
• Unattended transfer
• Call forward unconditional
• Call forward on Busy
• Call forward on No Answer
• Single line extension
• Find-me
• Call screening
• Simultaneous ringing
• Secondary number In/Out
• Do not disturb
• Call waiting
• Call Hold
• Consultation hold

40
Issues Discussion

• SIP can partially replace or complement existing
  mobility solutions
• Survivability under dynamic network condition
• When SIP server/proxy dies
• Registration with Local registrar vs. home
  registrar
• Both the end hosts moving
• SIP for Adhoc networking
• Fast handoff mechanism

41
Q/A
42
References

• www.research.telcordia.com/sip-mobile
• Application Layer Mobility Using SIP, MC2R
• Henning Schulzrinne, Elin Wedlund
• Application Layer Mobility Management Scheme for
  Wireless
• Internet, 3G Wireless Conference
• Dutta,Vakil, Baba, Chen,Tauil, Schulzrinne

43
SIP Mobility Demo for real-time audio
44
ITSUMO Outdoor Experiment
Morristown, NJ, U.S.A.
TARI Telcordia
45
ITSUMO Outdoor Experiment
Under the quasi-real environment
Purpose
-Mobility Test
-Total system feasibility check
46
ITSUMO Outdoor Experiment
Base Station
-Emulating cdma2000 by using WaveLAN
-Mobility test by using the eight radio cells
47
ITSUMO Outdoor Experiment
Driving route
300 m
48
ITSUMO Outdoor Experiment
Driving Experiment
-Evaluation of the IP mobility in terms of Micro,
Macro and Global Mobility
49
Mobile IP

• Mechanism developed for the network layer to
  support mobility
• Originally intended for travelers with laptops
  over wired networks
• Later adopted by the wireless community
• Maintains active TCP connections and UDP port
  bindings
• A mobile host is associated with a fixed IP
  address (home IP address)
• When a mobile host connects to a different
  network other than the one its IP address
  belongs, the home network forwards packets to it
• A router (home agent) on the users home network
  delivers the packets to the mobile host

50
Mobile IP
Foreign Network
Correspondent Host
Mobile Host
Foreign Agent
Home Agent
Home Network
51
Optimizations and Extensions to Base Mobile IP

• Triangular routing causes additional delays and
  wastes bandwidth
• If the correspondent host knows where the mobile
  host is, it can send packets directly to the
  care-of address of the mobile host
• Route optimization
• binding updates sent from a home agent upon
  request, or
• sent upon receiving a warning from a foreign
  agent if the mobile host changes location during
  a communication session
• Smooth handoff
• former foreign agent will keep forwarding packets
  to the new one until the correspondent host
  updates its mobility binding cache
• Theoretically triangular routing avoided, but
  correspondent host must be able to encapsulate
  packets - not possible without changing the
  operating system of the correspondent host

52
Optimizations and Extensions to Base Mobile IP
(contd.)

• Firewalls reject to forward packets coming from
  topologically incorrect addresses (hosts IP
  address does not match the network
• Reverse tunneling all packets from a mobile host
  go through the home agent
• triangular routing again !
• A mobile host registers with home agent each time
  it changes care-of address ? signaling delay for
  long distances
• Regional registration locally register within a
  visited domain
• hierarchical structure of foreign agents
• local foreign agents under a gateway foreign
  agent (GFA)
• home agent registers the GFAs address as the
  care-of address

53
Optimizations and Extensions to Base Mobile IP
(contd.)

• Network Assisted, Mobile and Network Controlled
  (NAMONC) handoff
• Faster handoff for real-time applications
• Network informs mobile host that a layer 2
  handoff is anticipated
• Uses simultaneous bindings (multiple
  registrations at a time), sends multiple copies
  of the traffic to potential movement locations
• Network Initiated, Mobile Terminated (NIMOT)
  handoff
• Foreign agents use layer 2 triggers to initiate a
  pre-registration prior to receiving a formal
  registration request from the mobile host
• Both methods assume considerable involvement of
  information from layer 2

54
Limitations and Inefficiencies of Mobile IP

• Encapsulation of packets adds between 8 or 12
  bytes and 20 bytes of overhead
• Although triangular routing is avoided with route
  optimization, with reverse tunneling it becomes a
  fact again
• With route optimization, changes are necessary in
  the operating systems of the correspondent hosts
• With regional registration, reliability an
  important issue (failure of a GFA will bring the
  whole hierarchy down)
• Processing time needed to encapsulate and
  decapsulate packets each time they traverse a
  home agent/foreign agent is not negligible
  especially for real-time sessions

55
Cellular IP (Columbia University, Ericsson)
Home Agent
Internet (with Mobile IP)
Correspondent Host
Gateway
BS
BS
BS
BS
56
Cellular IP

• Base stations snoop actual data packets from
  mobile hosts to gateway to cache the path taken
  by them
• To route packets from the gateway to the mobile
  host, base stations use the reverse of this path
• Hosts that have not transmitted packets for a
  while are removed from the routing cache of the
  base stations
• Idle hosts send infrequent paging-update packets
  to the gateway
• coarsely maintaining the position of idle hosts
  (passive connectivity)
• Active hosts exact locations are known
• If an active mobile host moves to another base
  station during a call
• it sends a route-update packet back to the
  gateway
• new base station(s) record this path accordingly

57
HAWAII (Bell Labs)
Internet
Domain 2
Domain 1
Domain Root Router
Domain Root Router
R
R
R
R
R
R
R
R
R
BS
BS
BS
58
HAWAII

• The path (route) between the mobile host and the
  domain root router is specific to that host
• established (during power-up) and updated (during
  movement) for that mobile host in the domain root
  router and intermediate routers
• This information is refreshed periodically by the
  mobile host
• Different path setup schemes possible to
  re-establish path states during handoff
• forward packets from the old base station to the
  new base station for a short period (until the
  relevant routers update their entries for the
  specific host)
• do not forward packets either bi-cast them to
  two base stations or unicast them for hosts that
  can simultaneously listen to two base stations.
• HAWAII requires all routers in a domain to be
  augmented with mobility support so that they are
  able to handle host-specific path setup messages

59
TeleMIP (Telcordia)

• TeleMIP is an intra-domain mobility solution
• It uses two layers of scoping within a domain
• Reduce the latency of intra-domain location
  updates by specifying an intra-domain termination
  point (Mobility Agent or MA).
• Intra-domain updates only up to the MA, which
  provides a globally valid COA to mobile host.
• Reduce the frequency of global update messages
• Since the MA is located at a higher hierarchy
  than that of subnets, global updates (to HA, CHs
  etc.) only occur for inter-domain mobility.
• Reduce the requirement of public addresses (IPv4)
• By promoting a two-level addressing scheme, it
  promotes the use of private (locally-scoped)
  addresses for handling intra-domain mobility.

60
TeleMIPs Architecture Layout
61
Mobile IP with Location Registers (MIP-LR)
(Telcordia, US Army)
Home Network a.b.c
HLR
2 Query
3 COA
Foreign Network j.k.l
CH
VLR
5Un-Encapsulated data packets sent directly to
COA
4 Binding cache (COA)
Mobile Host a.b.c.d
1 Registration COAj.k.l.m
62
MIP-LR

• HLR can be anywhere (geographically distributed)
• No tunneling
• After a mobile host moves
• if it was registered at some other foreign VLR,
  the new VLR deregisters it at the old VLR.
• If a VLR runs out of COAs temporarily, it issues
  its own IP address as COA ? tunnels packets
  temporarily
• After a mobile host moves
• correspondent host will have an outdated mobility
  binding
• a mechanism is required to update the cache on
  the correspondent host
• Lazy caching, eager caching and tunneling from
  old foreign agent to the new one

63
DHCP Enhancements for Mobile Wireless

• Requirement
• Rapid client configuration(milliseconds rather
  than seconds)
• Automatic client reconfiguration (independent of
  lease time)
• Efficient use of scarce wireless bandwidth
• Allowing clients to be routers
• Enhanced registration (e.g., user identification
  and security)
• Flexible proxies that can act both as
  relay/server
• Message exchange without broadcast
• How to achieve
• Shrink message size
• Minimize messages in transactions
• Minimize use of broadcast

64
DHCP
DRCP
Server
Client
DRCP ADVERTISEMENT(?)
DRCPDISCOVER
DRCPOFFER
DRCPACCEPT
65
DRCP Message Flow
Server
Client
Server
Client
ADVERTISEMENT
REQUEST/RELEASE
DISCOVER
ACK
OFFER
ACCEPT/DECLINE
Time axis
Extending the lease
Client moves to a new Domain
66
DRCP vs DHCP Messages

• DHCP - 236 bytes
• DRCP - 16 bytes
• 93.2 improvement

67
QoS scheme for the Mobile Testbed
CH(Correspondent Host)
Packet shaping for Real-Time Traffic (with
pre-reservation)
QLN
QGS
QLN
QLN
Initial SLS negotiation
Handoff(1)
Handoff(2)
MS w/Mobile IP
Handoff(3)
SLS change
Handoff(4)
ITSUMO Internet Technologies Supporting
Universal Mobile Operation
68
AAA Functional Model
Local Domain
Home Domain
AAAF
AAAH
A
AAAH Home AAA Server AAAF Foreign AAA Server A
Attendant(MIP FA, SIP server, ) C Client
C
Pre-established SA
69
Re-registration (SIP)
03/10/2001 095240237866 Sent to
207.3.232.905060 REGISTER sipresearch.telcordia
.com SIP/2.0 Via SIP/2.0/UDP 10.1.1.1305060 CSeq
1 REGISTER Expires 3600 Contact
sipdutta_at_10.1.1.1305060q0.00 From
sipdutta_at_research.telcordia.com Authorization
Basic bWlyaWFtOkJvb3N0ZXJzAPAY Call-ID
212114568_at_10.1.1.130 Date Sat, 10 Mar 2001
145240 GMT To sipdutta_at_research.telcordia.com
Content-Length 0
03/10/2001 095240236188 Sent to
207.3.232.905060 REGISTER sipresearch.telcordia.
com SIP/2.0 Via SIP/2.0/UDP 10.1.1.1305060 CSeq
1 REGISTER Expires 0 Contact
sipdutta_at_10.1.4.1315060 expires"Sat, 10 Mar
2001 154148 GMT" a ctionproxy q0.00 From
sipdutta_at_research.telcordia.com Authorization
Basic bWlyaWFtOkJvb3N0ZXJzAMDw Call-ID
212114567_at_10.1.1.130 Date Sat, 10 Mar 2001
145240 GMT To sipdutta_at_research.telcordia.com
Content-Length 0
70
Sample INVITE and Re-Invite
INVITE sipdutta_at_10.1.4.51 SIP/2.0 Via
SIP/2.0/UDP 10.1.4.1315060 CSeq 1
INVITE Contact sipdutta_at_10.1.4.1315060 Expires
3600 From sipdutta_at_dutta-lt4 Call-ID
172764989_at_10.1.4.131 Content-Type
application/sdp Priority normal Date Fri, 09
Mar 2001 022539 GMT To sipdutta_at_10.1.4.51 Cont
ent-Length 121 v0 odutta 482467205023
984104739 IN IP4 10.1.4.131 sUntitled cIN IP4
10.1.4.131 t0 0 maudio 10000 RTP/AVP 0
03/08/2001 212756924728 Sent to
10.1.4.515060 INVITE sipdutta_at_10.1.4.51
SIP/2.0 Via SIP/2.0/UDP 10.1.1.1305060 Contact
sipdutta_at_10.1.1.1305060 CSeq 2 INVITE From
sipdutta_at_dutta-lt4 Content-Type
application/sdp Date Fri, 09 Mar 2001 022756
GMT Call-ID 172764988_at_10.1.4.131 To
sipdutta_at_10.1.4.51 tag388643458667.10.1.4.51 Co
ntent-Length 121 v0 odutta 661157196696
984104876 IN IP4 10.1.1.130 sUntitled cIN IP4
10.1.1.130 t0 0 maudio 10000 RTP/AVP 0
71
Performance snapshot in 802.11 Environment

• INVITE - 455 bytes 100 msec processing time
  between msgs (OS dependent)
• Ringing - 223 bytes 5 msec for Invite to traverse
• OK - 381 bytes 70 msec for Re-Invite to traverse
  (mostly queuing delays)
• ACK - 261 bytes 150 msec for complete
  re-registration
• Bye - 150 bytes 100 msec for address acquisition
• De-Register - 370 bytes
• Re-Invite - 450 bytes
• Re-register - 425 bytes