5. What is CIFS?
• Common Internet File System
– Running on top of SMB “Server Message Blocks”
• CIFS is used for
– Directory Browsing
– File Transfer
– UNC paths
– Open/Read/Write/Close operations
• Common trait
– Many roundtrips per transaction
– Lots of meta data in relation to desired files
6. How Does WANScaler Accelerate CIFS?
• Anticipate requests based on learned behavior
• Read ahead in anticipation of the next data block
• Avoid compressing meta data
– CIFS engine communicates with compression module
8. How Does WANScaler Compression Work?
• Compression
– Replace a large data chunk with a small token. Send token instead –
acts as pointer
– WANScaler Methods:
– Disk Based Compression
– Memory Based Compression
• Unlike a web cache, WANScaler is not object or file aware. It is only bit stream
aware for TCP connections.
• The memory overwrites automatically when the history is full (FIFO).
9. WANScaler Compression Advantages
• Compression is configurable per service class though not
required
• WANScaler compression is application independent
• Requires zero configuration:
– Automatically chooses the best compression method dynamically:
– Disk-based compression (DBC)
– Memory-based compression
10. Multi-Level Compression
• Nested compression engines
– Disk-based compression: delivers up to 3500:1 compression for
disk matches.
– Memory-based compression: delivers 300:1 compression for
memory matches .
– Zlib
– LZS
• Automatic – nothing to configure. WANScaler algorithms use the best available
based on the situation
12. Typical TCP Flow Control
• Flow Control
– TCP does not know what the bandwidth of the link is!
Ethernet LAN, 10Mb/s, low latency and loss
x x x x
x x x x x x x
1 1
TCP Slow Start - packet sending rate
is increased after each round trip.
Slow
Start 2
TCP Congestion Control -Packet
Loss penalty = sending rate cut by
50%.
Congestion Control
2 Algorithm
X = packet loss
13. TCP On the WAN
T3, 45Mb/s, high latency and loss
x
x 1
1
x
2 High latency means a slower recovery
period during congestion control.
Slow
Start 2
Feedback (packet loss) is too infrequent
and ambiguous to be accurate.
Congestion Control
X = packet loss
14. TCP On the WAN
Performance (Mbps)
1. x x x x x x x x x x x Short Distance
Slow
Start
Long Distance
X = packet loss
Time (Milliseconds)
1. TCP Distance Bias
– Short distance sessions may have packet loss but recover quickly
– Long distance sessions are impacted by packet loss but recover slowly
2. The Result is Low Throughput and Random Application Delays
17. Typical WAN Communication
120 ms
Switch WAN Router WAN Router Switch
WAN
Client Server
SYN
SYN + ACK
ACK
18. Typical WAN Communication
120 ms
Switch WAN Router WAN Router Switch
WAN
Client Server
SYN
SYN + ACK
ACK
HTTP GET
19. Typical WAN Communication
120 ms
Switch WAN Router WAN Router Switch
WAN
Client Server
SYN
SYN + ACK
ACK
HTTP GET
ACK+Data
20. Typical WAN Communication
120 ms
Switch WAN Router WAN Router Switch
WAN
Client Server
SYN
SYN + ACK
ACK
HTTP GET
ACK+Data
ACK
21. TCP Flow Control with WANScaler
120 ms
Switch WAN WAN Switch
Router Router
WAN Server
Client
22. TCP Flow Control with WANScaler
120 ms
Switch WANScaler WAN WAN WANScaler Switch
Router Router
WAN Server
Client
23. TCP Flow Control with WANScaler
Fast Side Slow Side Slow Side Fast Side
120 ms
Switch WANScaler WAN WAN WANScaler Switch
Router Router
WAN Server
Client
SYN
SYN+ACK
ACK
HTTP GET
ACK
ACK
ACK
24. WANScaler Flow Control
120 ms
Switch WANScaler WAN WAN WANScaler Switch
Router Router
WAN Server
Client
Each Segment has its own flow control:
– Commonly deployed TCP Windows are 64kB max.
– On the WAN side, WANScaler increases the Window to 8MB (RFC
1323)
– WANScaler acknowledges packets on the LAN side, so server keeps
sending
Use rate-based sender on the WAN segment. Never send
faster than the configured link speed
26. Location based ICA Optimisation
Branch Office/Regional Site
Citrix Repeater
Corporate LAN/Data Center
Based on the well known optimisation technologies, already known from the ICA Client
Caching function taken away from the client, and taken into the data center (Citrix Repeater).
So it can be used by ANY user at the data center location !
27. Optimisation of GUI-, print- and data transfer
Branch Office/Regional Site
Corporate LAN/Data Center
28. System requirements for ICA Acceleration
For the first release: • Supported Appliances
• XenApp Client • Branch Repeater (Windows Server)
Version 1.5
• 32-bit Windows PC* • Branch Repeater (Linux) on Version 5.0
• 11.0 • WANScaler 8000 Series with version 5.0
• WANScaler Client offers ONLY TCP
• XenApp Server Acceleration**
• ONLY 32-bit Windows Server 2003
• XA Server Version 4.5 or 5.0
• HRP03 with post Acceleration HF
29. Scenario # 1:
• ICA user uses the same Citrix Repeater Box:
1. Different users, by using the same ICA window size and resolution, that
access the same texts, numbers etc. (z.B. Word or Excel)
Example: Two users open the same document, but data will only be transferred once.
30. Scenario # 2:
• ICA user uses the same Citrix Repeater Box:
2. Different users, that use the same ICA window size and resolution, scrolling
within the same document.
Example: Different users are using form or browser based appplications with identical background
objects. Redundant data will not be transferred.
31. Support of mixed environments
HQ/Data Center
Branch Office
Internet/WAN
Branch Repeater Citrix Repeater
or WANScaler
Branch Office
For users WITHOUT WanScaler /Branch Repeater Box or with an older ICA Client it all stays the same!
32. Case Study #1
Example of a non optimised environment
WAN XenApp Server 4.5
50 ICA users MPLS
15% ICA data traffic 10 - 45 Mbps Mainly usage of the
> 180 ms Internet Explorer
85% non ICA data traffic
40% line utilisation ng
Environment:
• Slow applications through a slow network (high latency)
• But nearly no usage of same/redundant ICA data
• No repeatable application scenario (Usage of same data/documents)
33. Case Study #2
Company with branch offices and a centralised serverfarm
WAN XenApp Server 4.5
20 ICA users DSL or fractional T1 (256 kbps – 768 kbps)
>95% ICA data traffic 50 ms MS Office
>90% line utilisation Printing
File sharing
Environment:
• Users use same Word and Excel files
• Printing is an important, and frequently used function
• Users very often copy files (via ICA) from or to centralised file servers
34. Case Study #3
Central server farm, big amount if print data
WAN XenApp Server 4.5
30 ICA users MPLS
>75% ICA data traffic 1.5 Mbps ERM Software
~ 50 ms Web Portal
>90% line utilisation
Printing of PDF files
Environment:
• Slow Response times (applications) by large, and frequently used PDF-Print files
• Usage of WEB based Portals and ERM software. Access on same Datensätze.
• No usage of MS Office applications and Client Drive Mapping
35. ICA Acceleration - facts
Ideal for print data, CDM file transfer and MS Office as well as applications with many
identical window contents
NOT ideal for Adobe/CAD applications as there are only few opportunities for
compression and nearly no redundant data
ICA screen resolution makes the difference. Same resolution is optimal. Differentiating
resolution means more (per resolution) data traffic and a larger amount of data within
the Citrix Repeater Cache.
36. ICA Acceleration - facts
• Optimal, when many ICA users utilise the same Citrix Repeater Box:
Different users are accessing under usage of the same ICA window size and resolution
based on identical data (example: Word or Excel)
Same or different users are blättern within the same file under usage of the same ICA
window size and resolution
Different or identical users are printing the same files via ICA
Duplication of same files under usage of ICA Client Drive Mapping.
Example: local storage of mail attachments from a published Outlook
37. Six Keys to Successful Application Delivery
Citrix® NetScaler®
Deliver Web Applications
Citrix
XenApp
Server™
Deliver Windows
Citrix EdgeSight™ Citrix Repeater™ Citrix Access Applications
Users Monitor End User Accelerate Apps Gateway™ Apps
Experience to Branch Users Enable Secure
Citrix XenDesktop™
Application
Access Deliver Desktops