Communications Efficiency Sandeep K. Singhal, Ph.D Director, Windows Networking Microsoft...
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Transcript of Communications Efficiency Sandeep K. Singhal, Ph.D Director, Windows Networking Microsoft...
Communications Efficiency
Sandeep K. Singhal, Ph.DDirector, Windows Networking
Microsoft Corporation
Agenda
• Trends in enterprise networking• Windows Vista and Windows Server 2008• Collaboration with MoD• Looking into the future• Summary
Trends in Enterprise Networking
Server consolidation and growth of data
centers
Increasingly mobile and remote staff
Evolving security requirements
Trends in Enterprise Networking
• Single networking fabric for web, file, database, and backup• Increased network traffic load on servers• Increased load on Internet firewalls
Server consolidation and growth of data
centers
Increasingly mobile and remote staff
Evolving security
requirements
Trends in Enterprise Networking
• Single networking fabric for web, file, database, and backup• Increased network traffic load on servers• Increased load on Internet firewalls
Server consolidation and growth of data
centers
• Remote access solutions stretch experience, support, and management
• Greater reliance on WAN (over Internet) links from branch offices
• Multiple client access technologies and devices
Increasingly mobile and remote staff
Evolving security
requirements
Trends in Enterprise Networking
• Single networking fabric for web, file, database, and backup
• Increased network traffic load on servers• Increased load on Internet firewalls
Server consolidation and growth of data
centers
• Remote access solutions stretch experience, support, and management
• Greater reliance on WAN (over Internet) links from branch offices• Multiple client access technologies (e.g., WLAN, WWAN,
satellite) and devices (smartphones, laptops, unmanaged home PCs, etc.)
Increasingly mobile and remote staff
• Enterprise edge disappearing with mobile workforce & devices • Heterogeneous user population (contractors, vendors) require
securing resources in addition to networks• Federation and regulatory needs require policy-based isolation
domains
Evolving security
requirements
Windows Vista and Windows Server 2008
Windows Vista and Windows Server 2008:Networking Stack Architecture
Win
do
ws
Filterin
g
Platfo
rm
IPv4
802.3
WSK
WSK Clients TDI Clients
NDIS
WLAN 1394 Loop-back
IPv4 Tunnel
IPv6 Tunnel
IPv6
RAWUDPTCP
Next-Generation TCP/IP Stack (tcpip.sys)
AFD
TDX
TDI
Winsock User Mode
Kernel Mode
Key Networking Innovations
• Network performance• Connectivity• Security• PC health management• Scalability• Enterprise quality of service (eQoS)• Peer-to-peer and ad-hoc collaboration
Key Networking Innovations
• Network performance• Connectivity• Security• PC health management• Scalability• Enterprise quality of service (eQoS)• Peer-to-peer and ad-hoc collaboration
The Performance Challenge• Network stack implementations limited by
– Static default configurations picked to match most common environments
– Protocols designed more than a decade ago
• Poor network performance under– High latency (e.g., access to resources across the continent)– High bandwidth (e.g., fiber to the home [FTTH])– Losses (e.g., WLAN, WWAN, satellite networks)
• Network performance is key determinant of performance of most applications
The Receive Window Limitation
North America
IntercontinentalFiber
Satellite
Autotuning Receive Window• Problem: Network performance limited on high-latency WAN
(such as satellite or FTTH)– TCP default receive window limits throughput to 5Mbps on a 100ms
(coast to coast) connection– Even lower throughput on higher latency like inter-continent or
satellite
• Solution: Windows Vista and Windows Server 2008 adjust TCP Receive Window for each connection over time– Window scaling (RFC 1323) enabled by default with scale factor of 8– Estimates bandwidth delay product and application read-rate
• Impact: Applications see faster uploads/downloads– SMB file copy between Redmond and Australia improved 10x– Backup between Bay area and Tukwila data center improved 40x– Benefit varies depending on spare capacity
Thr
ough
put
(Mbp
s)Application Performance
with Windows Vista and Windows Server 2008
Microsoft.com and Receive Window Auto-Tuning
• Replicating data between Redmond and Bay Area– 1 Gbps dedicated connectivity
• Default configurations• On Windows Server 2003 SP1:
– 100Mbps NICs, 10Mbps throughput
• On Windows Vista:– 100Mbps NICs, 80Mbps throughput– 1000Mbps NICs, 400Mbps throughput (memory to memory
copy)• File copy from disk to disk limited to 250Mbps due to disk
bottleneck
40X
Protocol Limitations: Dealing with High Bandwidth
• Scenario: Replication between geographically distributed data centers connected by gigabit links– TCP protocols cuts down sending rate dramatically on losses and
increases sending rate slowly• < 1 in 83000 packet loss rate to fully occupy a 1Gbps/100ms link
• Solution: Compound TCP utilizes loss and delay information to rapidly ramp up sending rate without causing losses– Fairness is important: <10% impact on existing TCP connections– Enabled by default on Windows Server 2008 (only send side support
needed)
• Impact: Faster data center replication– Microsoft.com replication time reduced by half
Sample CTCP Performance
0
200
400
600
800
1000
1200
1400
1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190
Time (sec)
Th
rou
gh
pu
t (M
bp
s)
CTCP
NewReno
• TCP data transfer using Compound-TCP (blue) and vanilla TCP (red) between Bay Area, CA and Tukwila, WA data centers
Protocol Limitations: Dealing with Random Losses
• Scenario: Wireless networks like GPRS, UMTS, WLAN– Losses interpreted by TCP as indication of congestion– Link layer recovery exacerbates problem as TCP does recovery at its own
layer (spurious retransmissions)– Large change in round trip times causes fatal TCP connectivity loss
• Solution:– Detect spurious retransmissions using Forward Retransmission Timeout
Recovery (FRTO) and Delayed Selective Acknowledgement (DSACK) mechanisms (IETF based)
• Avoid unnecessary retransmission and also reduction in sending rate– RTT resiliency mechanism
• Impact: Improved wireless performance– 10-30% throughput improvement in GPRS scenarios
Key Networking Innovations
• Network performance• Connectivity• Security• PC health management• Scalability• Enterprise quality of service (eQoS)• Peer-to-peer and ad-hoc collaboration
Drivers for IPv6
Scalable Network Connectivity
Seamless Application Development platform
End-to-end Authentication
Simplified Ad-hoc Network support
IPv6: Ready, Real and Required with Windows Vista and Windows Server 2008
• Ready– Enabled by default and preferred on Windows Vista and Windows
Server 2008– All out-of-box applications, services, and interfaces support IPv6 (dual
stack or native)– IPv6 is being deeply integrated across our entire product line
• Real– Usable on existing IPv4 networks – Transition technologies (ISATAP, 6to4, Teredo) enable low-cost,
automatic IPv6 deployment
• Required– Scenarios such as Windows Meeting Space and Remote Assistance have
unique value in IPv6 networks
IPv6 Migration Strategy
Infrastructure Migration Application Migration Operations Migration
Baseline Architecture
Planning, Training, Testing
Security
Target Architecture
IPv6 Migration ApproachOperations Migration
• Network Management
• Infrastructure Services
• Security
Action Items: Host monitoring Application
configuration License
management Patch update
Application Migration
• Commercial Apps• Line of Business Apps
Action Items: Inventory & Assess
Impact Application porting Application
deployment Proxy for applications
that can’t migrate
Infrastructure Migration
• Tunneling• Dual Stack• Native v6
Action Items: Upgrade to Windows
Vista Ensure DNS supports
IPv6 Deploy ISATAP server
or native addressing
IPv6 Migration:Options and Costs
Method Requirement Cost Availability
Transition Technologies ISATAP, 6to4 Lowest
Many Platforms, Including
Windows 2003
Dual Stack Some hardware upgrades Medium Most hardware
supports v6
Native IPv6All hardware
upgraded, applications
testedHighest
Many software vendors still don’t
support IPv6