Beware of Specials
I bought this at harbor town cause its on special, guess what happen when i got home & pill the 1st stick off.
hey! the price increased each time they do a massive discount, i guess its normal for any businesses.
so look out & ask is it really what you need?
Monday, September 24, 2012
Sunday, September 23, 2012
RANCID - linux is cool
i haven't got much linux experiences but here is the setup steps for me
i haven't got much linux experiences but here is the setup steps for me
sudo
apt-get update
Adduser
rancid
Sudo
Apt-get install rancid cvsweb mutt postfix
Sudo nano
/etc/rancid/rancid.conf
LIST_OF_GROUPS="brisbane"
Sudo nano /etc/aliases
rancid-brisbane: rancid
rancid-admin-brisbane: rancid
Rancid: myemail@mycompany.com
newaliases
Sudo Chown -R rancid /var/lib/rancid
Sudo Chmod -R 775 /var/lib/rancid
Sudo Chown rancid logs
Sudo Chmod 775 /var/lib/rancid/logs
Cd
/var/lib/rancid/logs
Sudo Chmod 775 .
/etc/postfix/main.cf
Add
smtp.mycompany.com
postfix
restart
Su rancid
/var/lib/rancid/bin/rancid-cvs
cd /var/lib/rancid/brisbane
nano router.db
IPADDRESS_OR_HOSTNAME:brand:up_or_down
nano /home/rancid/.cloginrc
add
autoenable * 1
add method * telnet
add user
10.11.61.11 admin
add
userpassword 10.11.61.11 passwordhere
add password IPADDRESS_OR_HOSTNAME LOGINPASSWORD
ENABLEPASSWORD
add password OTHERIP_OR_HOSTNAME LOGINPASSWORD
ENABLEPASSWORD
chmod 640 /home/rancid/.cloginrc
chown rancid /home/rancid/.cloginrc
####- no
need usermod -a -G
sudo rancid
Rancid-run
Check
router config
/var/lib/rancid/CVS/brisbane/configs
Check
rancid log
/var/lib/rancid/logs
> crontab -e
- Add this line:
*/30 * * * * /usr/lib/rancid/bin/rancid-run
- Add this line:
*/30 * * * * /usr/lib/rancid/bin/rancid-run
Add the Web GUI:
apt-get install cvsweb
nano /etc/cvsweb/cvsweb.conf
Find "@CVSrepositories"
Add:
'rancid' => ['Rancid', '/var/lib/rancid/CVS'],
Save and Quit
Restart apache
apache2ctl restart
sudo ~rancid/bin/rancid-run (or, if in as root, rancid-run)
You can now open a web browser to http://IPOFSERVER/cgi-bin/cvsweb
Too Much
Information:
If you feel like you only want to
have the configuration files and not the proc info/mem info etc, just edit the
following file:
nano /var/lib/rancid/bin/rancid
Search for "# Main"
Comment out lines you no longer
wish to document
Save and Quit
Thursday, September 6, 2012
Sharing a few good sites
do you want to do programming? here is the click and drag way! thanks MIT
http://sikuli.org/
watching BBC/Discovery outside of US/UK?
http://tunlr.net/
wanna listen to all the music, incl eng/chinese/jap?
http://grooveshark.com/
of coz if need a bargin here!
http://www.ozbargain.com.au/
do you want to do programming? here is the click and drag way! thanks MIT
http://sikuli.org/
watching BBC/Discovery outside of US/UK?
http://tunlr.net/
wanna listen to all the music, incl eng/chinese/jap?
http://grooveshark.com/
of coz if need a bargin here!
http://www.ozbargain.com.au/
High
Performance Computing (HPC) on AWS
Pasted
from <http://aws.amazon.com/hpc-applications/>
GPC come on!
Sunday, August 26, 2012
Wednesday, July 4, 2012
Windows 7 Dual Nic Routing
When more than one network connection is available, Windows uses the
one with the lowest metric value. By default, it automatically
assigns a metric value based on the network connection's rated speed:
An explanation of the Automatic Metric feature for Internet Protocol
routes
http://support.microsoft.com/?id=299540
To force Windows to use a specific network connection, assign a metric
value to each one, giving the lowest value to the desired connection:
1. Open the Network Connections folder.
2. Right click the desired connection.
3. Click Properties > Internet Protocol (TCP/IP).
4. Click Properties > Advanced.
5. Un-check "Automatic metric".
6. Enter a number between 1 and 9999 for the "Interface metric".
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Desktop Experience)
When more than one network connection is available, Windows uses the
one with the lowest metric value. By default, it automatically
assigns a metric value based on the network connection's rated speed:
An explanation of the Automatic Metric feature for Internet Protocol
routes
http://support.microsoft.com/?id=299540
To force Windows to use a specific network connection, assign a metric
value to each one, giving the lowest value to the desired connection:
1. Open the Network Connections folder.
2. Right click the desired connection.
3. Click Properties > Internet Protocol (TCP/IP).
4. Click Properties > Advanced.
5. Un-check "Automatic metric".
6. Enter a number between 1 and 9999 for the "Interface metric".
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Desktop Experience)
Dest Ip Netmask Gateway
route ADD 10.0.0.0 MASK 255.255.255.0 10.0.0.1
http://www.ni.com/white-paper/12558/en
http://serverfault.com/questions/21455/how-to-configure-dns-on-windows-with-multiple-nics
http://superuser.com/questions/337763/is-there-a-good-dns-server-i-can-install-on-windows-7-for-a-lan
Tuesday, June 12, 2012
Netgear ReadyNAS 3TB issues
NV+ V1 not support 3TB drive
NV+ V1 Revision V2 not support 3TB
NV+ V2 support 3TB
Similarly with the NV+ v1
and the NV+ v2
http://www.rnasguide.com/2012/01/09/how-to-tell-whether-i-have-a-duo-v1-or-duo-v2-or-nv-v1-or-nv-v2/
Readynas Compatibility List
http://www.readynas.com/hcl
NV+ V1 not support 3TB drive
NV+ V1 Revision V2 not support 3TB
NV+ V2 support 3TB
Note:
Unfortunately Netgear decided to name the new ARM based series of the ReadyNAS product line quite similar to the old Sparc products. So make sure to not confuse the Sparc based Duo/NV+ with their newer cousins Duo v2/NV+ v2. To make matters worse there are Duos on the market that have a "v2" sticker on their back - which actually means "Duo (v1) hardware revision v2". To easily identify what version of the Duo/NV+ you own, just open up the web interface for managing your ReadyNAS. They are quite different on the ARM based products.
- On Sparc based products the web interface looks like this:
- On ARM based products it will look like this:
Physical difference
Similarly with the NV+ v1
and the NV+ v2
http://www.rnasguide.com/2012/01/09/how-to-tell-whether-i-have-a-duo-v1-or-duo-v2-or-nv-v1-or-nv-v2/
Readynas Compatibility List
http://www.readynas.com/hcl
A Few storage protocol compare
while i was doing some research on VMware, i also checking out storage performance.
iscsi, FCOE, FC
speed almost similar!!!
http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101686
http://www.unifiedcomputingblog.com/?p=264
http://www.experts-exchange.com/Storage/Storage_Technology/Q_26337065.html
http://www.scribd.com/doc/82545381/EVA-v-P4000-A-Discussion
while i was doing some research on VMware, i also checking out storage performance.
iscsi, FCOE, FC
speed almost similar!!!
http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101686
http://www.unifiedcomputingblog.com/?p=264
http://www.experts-exchange.com/Storage/Storage_Technology/Q_26337065.html
http://www.scribd.com/doc/82545381/EVA-v-P4000-A-Discussion
Tuesday, May 22, 2012
MPLS VPN with ASA IPSEC BACKUP
the issue is when link R2 to PE2 is down, R1 will connect to R2 with no issue, but how other site connected to MPLS cloud gets the update? BGP?
https://supportforums.cisco.com/docs/DOC-5748
the issue is when link R2 to PE2 is down, R1 will connect to R2 with no issue, but how other site connected to MPLS cloud gets the update? BGP?
https://supportforums.cisco.com/docs/DOC-5748
Monday, May 21, 2012
MPLS beginning - learning to become an ISP
base on learning Telstra network
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6557/prod_white_paper0900aecd8051fbdc.html
http://irwanp.wordpress.com/2009/02/16/inter-as-mpls-vpn-using-mp-ebgp-vpnv4/
nbn consideration: http://www.nbnco.com.au/assets/documents/nbn-co-information-pack.pdf
http://www.nbnco.com.au/assets/documents/nbn001-concept-paper-final-dec-09.pdf
http://www.itnews.com.au/News/155871,quigley-offers-isps-a-rough-sketch-of-nbn-architecture.aspx
http://www.telstrabusiness.com/business/ShowDoc?nodePath=%2FBEA+Repository%2FResources%2FFiles%2FWhite+Papers%2FPDF_HowToSelectAustralianMPLSProviders//binary&versionId=2
ISIS or OSPF
http://www.menog.net/menog-meetings/menog4/presentations/MENOG4-ISIS-Tutorial.pdf
base on learning Telstra network
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6557/prod_white_paper0900aecd8051fbdc.html
http://irwanp.wordpress.com/2009/02/16/inter-as-mpls-vpn-using-mp-ebgp-vpnv4/
nbn consideration: http://www.nbnco.com.au/assets/documents/nbn-co-information-pack.pdf
http://www.nbnco.com.au/assets/documents/nbn001-concept-paper-final-dec-09.pdf
http://www.itnews.com.au/News/155871,quigley-offers-isps-a-rough-sketch-of-nbn-architecture.aspx
http://www.telstrabusiness.com/business/ShowDoc?nodePath=%2FBEA+Repository%2FResources%2FFiles%2FWhite+Papers%2FPDF_HowToSelectAustralianMPLSProviders//binary&versionId=2
ISIS or OSPF
http://www.menog.net/menog-meetings/menog4/presentations/MENOG4-ISIS-Tutorial.pdf
Sunday, May 20, 2012
MTU - PING
ADSL set MTU 1480
ethernet 1500byte
MSS = 1500-20(ip)-20(tcp) = 1460
therefore, 1452 + 20 (IP) + 8byte (ICMP) = 1480
C:\Users\jonny>ping 8.8.8.8 -f -l 1452
Pinging 8.8.8.8 with 1452 bytes of data:
Reply from 8.8.8.8: bytes=1452 time=48ms TTL=56
Reply from 8.8.8.8: bytes=1452 time=48ms TTL=56
http://smallvoid.com/article/tcpip-mtu-size.html
http://www.zytrax.com/tech/protocols/tcp.html
http://www.cisco.com/en/US/tech/tk175/tk15/technologies_tech_note09186a0080093bc7.shtml
ADSL set MTU 1480
ethernet 1500byte
MSS = 1500-20(ip)-20(tcp) = 1460
therefore, 1452 + 20 (IP) + 8byte (ICMP) = 1480
C:\Users\jonny>ping 8.8.8.8 -f -l 1452
Pinging 8.8.8.8 with 1452 bytes of data:
Reply from 8.8.8.8: bytes=1452 time=48ms TTL=56
Reply from 8.8.8.8: bytes=1452 time=48ms TTL=56
http://smallvoid.com/article/tcpip-mtu-size.html
http://www.zytrax.com/tech/protocols/tcp.html
http://www.cisco.com/en/US/tech/tk175/tk15/technologies_tech_note09186a0080093bc7.shtml
Friday, May 18, 2012
Digital Voice Port Pinout (RJ-48C)
http://www.cisco.com/en/US/services/ps2827/ps2978/services_at_a_glance_smartnet.pdf
Pin | Signal | |
---|---|---|
1 | Receive (Rx) Tip | |
2 | Rx Ring | |
3 | Not used | |
4 | Transmit (Tx) Tip | |
5 | Tx Ring | |
6 | Not used | |
7 | Not used | |
8 | Not used |
Ethernet patch port
Thursday, May 17, 2012
Recommended Book List
Network Warrior Gary A. Donahue - network engineer must read, this book have everything you needed to become an engineer not just technically but also from all other aspect.
Network Warrior Gary A. Donahue - network engineer must read, this book have everything you needed to become an engineer not just technically but also from all other aspect.
Wednesday, May 16, 2012
CUCM 6.1(2) - 8.6
just garthering my documents
http://ciscovoiceguru.com/6177/cucm-upgrades-major-versions/
http://www.tek-tips.com/viewthread.cfm?qid=1557847
http://www.cisco.com/en/US/docs/voice_ip_comm/uc_system/unified/communications/system/versions/IPTMtrix.html#wp1016708
http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/ps5748/ps378/prod_brochure0900aecd8062a4f9.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/rel_notes/8_6_2/cucm-rel_notes-862a.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cusrst/requirements/guide/srs86spc.htm
http://en.wikipedia.org/wiki/Cisco_Unified_Communications_Manager
http://www.gossamer-threads.com/lists/cisco/voip/159692?do=post_view_flat#159692
http://www.mentby.com/Group/cisco-voip/upgrading-cm-from-42-to-86-ios-upgrade-required.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/docguide/8_6_2/dg862a.html
http://www.cisco.com/en/US/products/sw/voicesw/ps556/tsd_products_support_series_home.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/requirements/guide/33matrix.htm
https://puck.nether.net/pipermail/cisco-voip/2011-November/025050.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/install/8_6_1/install/cmins861.html
http://www.netcraftsmen.net/blogs/cisco-mobile-client-update.html
https://supportforums.cisco.com/docs/DOC-9124#/?page=2
https://supportforums.cisco.com/thread/2120218
7.1(2b)SU1 - direct upgrade
then 7.1(5b)SU5 / 7.1(3b)SU2 - >8.6
current support
http://www.cisco.com/en/US/prod/voicesw/ps6788/vcallcon/ps556/end_of_life_notice_c51-589088.html
http://tools.cisco.com/ITDIT/vtgsca/VTGServlet
https://supportforums.cisco.com/thread/2011367
https://supportforums.cisco.com/thread/2077678
http://www.gossamer-threads.com/lists/cisco/voip/140652
http://ciscoccvp.wordpress.com/tag/cisco-srst/
https://supportforums.cisco.com/thread/2078086
http://smbitsolutions.wordpress.com/2012/02/27/all-about-cisco-unified-srst/
just garthering my documents
http://ciscovoiceguru.com/6177/cucm-upgrades-major-versions/
http://www.tek-tips.com/viewthread.cfm?qid=1557847
http://www.cisco.com/en/US/docs/voice_ip_comm/uc_system/unified/communications/system/versions/IPTMtrix.html#wp1016708
http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/ps5748/ps378/prod_brochure0900aecd8062a4f9.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/rel_notes/8_6_2/cucm-rel_notes-862a.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cusrst/requirements/guide/srs86spc.htm
http://en.wikipedia.org/wiki/Cisco_Unified_Communications_Manager
http://www.gossamer-threads.com/lists/cisco/voip/159692?do=post_view_flat#159692
http://www.mentby.com/Group/cisco-voip/upgrading-cm-from-42-to-86-ios-upgrade-required.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/docguide/8_6_2/dg862a.html
http://www.cisco.com/en/US/products/sw/voicesw/ps556/tsd_products_support_series_home.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/requirements/guide/33matrix.htm
https://puck.nether.net/pipermail/cisco-voip/2011-November/025050.html
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/install/8_6_1/install/cmins861.html
http://www.netcraftsmen.net/blogs/cisco-mobile-client-update.html
https://supportforums.cisco.com/docs/DOC-9124#/?page=2
https://supportforums.cisco.com/thread/2120218
7.1(2b)SU1 - direct upgrade
then 7.1(5b)SU5 / 7.1(3b)SU2 - >8.6
current support
http://www.cisco.com/en/US/prod/voicesw/ps6788/vcallcon/ps556/end_of_life_notice_c51-589088.html
http://tools.cisco.com/ITDIT/vtgsca/VTGServlet
https://supportforums.cisco.com/thread/2011367
https://supportforums.cisco.com/thread/2077678
http://www.gossamer-threads.com/lists/cisco/voip/140652
http://ciscoccvp.wordpress.com/tag/cisco-srst/
https://supportforums.cisco.com/thread/2078086
http://smbitsolutions.wordpress.com/2012/02/27/all-about-cisco-unified-srst/
Monday, May 14, 2012
Ip addressing rule
When allocating IP address space, endeavor to allocate a block that can be referenced
with a single access list entry.
Always allocate more IP address space than is originally requested.
GAD¡¯s Maxim #1: Network designs are based on politics, money, and
the right way to do it¡Âªin that order.
GAD¡¯s Maxim #2: The only valid reasons to change a properly
sized production network are simplification, standardization, and
stabilization.
GAD¡¯s Maxim #3: Companies only spend money on IT projects that
lower costs, increase performance or capacity, or increase reliability.
When allocating IP address space, endeavor to allocate a block that can be referenced
with a single access list entry.
Always allocate more IP address space than is originally requested.
GAD¡¯s Maxim #1: Network designs are based on politics, money, and
the right way to do it¡Âªin that order.
GAD¡¯s Maxim #2: The only valid reasons to change a properly
sized production network are simplification, standardization, and
stabilization.
GAD¡¯s Maxim #3: Companies only spend money on IT projects that
lower costs, increase performance or capacity, or increase reliability.
PathTest
my new tool for WAN link speed testing
http://blog.appneta.com/2011/12/27/iperf-and-pathtest-an-engineers-experiment/
http://www.testmypath.com/
my new tool for WAN link speed testing
http://blog.appneta.com/2011/12/27/iperf-and-pathtest-an-engineers-experiment/
http://www.testmypath.com/
Sick of small company email inbox?
I know lots of company still using exchange as office email solution where the cloud is not as stable as it yet.
however for personal emails instead using PST now you can use hotmail to do you backup 5GB space :)
you will need to an outlook hotmail connector, and follow below link.
once installed, you will have hotmail as a separate mailbox for you to drag and drop
http://office.microsoft.com/en-us/outlook/microsoft-office-outlook-hotmail-connector-overview-HA010222518.aspx
http://windowsteamblog.com/windows_live/b/windowslive/archive/2011/11/15/10-reasons-to-switch-to-hotmail-if-you-use-outlook.aspx
I know lots of company still using exchange as office email solution where the cloud is not as stable as it yet.
however for personal emails instead using PST now you can use hotmail to do you backup 5GB space :)
you will need to an outlook hotmail connector, and follow below link.
once installed, you will have hotmail as a separate mailbox for you to drag and drop
http://office.microsoft.com/en-us/outlook/microsoft-office-outlook-hotmail-connector-overview-HA010222518.aspx
http://windowsteamblog.com/windows_live/b/windowslive/archive/2011/11/15/10-reasons-to-switch-to-hotmail-if-you-use-outlook.aspx
Cisco 877 ADSL by pass
if you need following kind of design use this on 877
---adsl router ---cisco 1811 router---lan
by pass external IP/FW
!
interface ATM0
no ip address
no atm ilmi-keepalive
pvc 8/35
encapsulation aal5snap
!
dsl operating-mode auto
bridge-group 1
!
!
interface Vlan1
no ip address
bridge-group 1
!
bridge 1 protocol ieee
!
http://forums.whirlpool.net.au/archive/920734
if you need following kind of design use this on 877
---adsl router ---cisco 1811 router---lan
by pass external IP/FW
!
interface ATM0
no ip address
no atm ilmi-keepalive
pvc 8/35
encapsulation aal5snap
!
dsl operating-mode auto
bridge-group 1
!
!
interface Vlan1
no ip address
bridge-group 1
!
bridge 1 protocol ieee
!
http://forums.whirlpool.net.au/archive/920734
Sunday, May 13, 2012
UDT: UDP-based Data Transfer
-for High-Speed Wide Area Networks
If you have a LFN network and haven't got an WAAS device, try this below.
http://udt.sourceforge.net/
http://forums.networkinfrastructure.info/general-discussion/advice-needed-on-wan-performance-lfn-connection/
Full Mesh WIFI
Great idea!
like to have this protocol build in to every device so you will always have some time of connectivity.
http://owni.fr/files/2011/09/Building_a_Rural_Wireless_Mesh_Network_-_A_DIY_Guide_v0.7_65.pdf
Great idea!
like to have this protocol build in to every device so you will always have some time of connectivity.
http://owni.fr/files/2011/09/Building_a_Rural_Wireless_Mesh_Network_-_A_DIY_Guide_v0.7_65.pdf
Saturday, May 12, 2012
Cisco VPN config guide
http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a008009448f.shtml
ASA
8.x : Allow Split Tunneling for AnyConnect VPN Client on the ASA Configuration
Example - Cisco Systems
http://www.techrepublic.com/blog/networking/eight-easy-steps-to-cisco-asa-remote-access-setup/1201
http://www.techrepublic.com/blog/networking/eight-easy-steps-to-cisco-asa-remote-access-setup/1201
after modification to accesslist
clear crypto isakmp
ASIC Port Mapping
6500-1#show interface capabilities module 2
balababababaab
Link Debounce Time: yes
Ports-in-ASIC (Sub-port ASIC) : 1-24 (1-12)
Remote switch uplink: no
Ports-in-ASIC (Sub-port ASIC) : 1-24 (1-12)
Remote switch uplink: no
balbababaa
4500-1#show platform mapping ports interface gigabitEthernet 3/1
Interface Gigaport Phyport Aggport PimPhyport
Gi3/1 23 185 1 0
Interface Gigaport Phyport Aggport PimPhyport
Gi3/1 23 185 1 0
3120X-1#sh platform pm if-numbers
interface gid gpn lpn port slot unit slun port-type lpn-idb gpn-idb
----------------------------------------------------------------------
Gi1/0/1 1 1 1 1/6 1 1 1 local Yes Yes
----------------------------------------------------------------------
Gi1/0/1 1 1 1 1/6 1 1 1 local Yes Yes
Thursday, May 10, 2012
911 coverup
who knows the big picture?
its all start when ppl start question why building 7 is a pre-planed demolition?
http://en.wikipedia.org/wiki/7_World_Trade_Center
http://www.youtube.com/watch?v=7OE3Adu4l0g
who knows the big picture?
its all start when ppl start question why building 7 is a pre-planed demolition?
http://en.wikipedia.org/wiki/7_World_Trade_Center
http://www.youtube.com/watch?v=7OE3Adu4l0g
LFN - issues
http://www.riverbed.com/docs/TechOverview-Riverbed-RiOS.pdf
http://packetlife.net/blog/2010/aug/4/tcp-windows-and-window-scaling/
http://en.wikipedia.org/wiki/HSTCP
http://tools.ietf.org/html/rfc1323
http://en.wikipedia.org/wiki/Bandwidth-delay_product
http://en.wikipedia.org/wiki/Round-trip_delay_time
http://community.riverbed.com/t5/Steelhead-Appliance/hs-tcp-questions/td-p/5564
http://cisconet.com/traffic-analysis/traffic-analysis-general/413-internet-speed-issue-why-tcp-window-size-is-matter.html
http://www.networkworld.com/details/7591.html
http://research.microsoft.com/en-us/um/people/padhye/tcpworkshop/slides/raj_jain_high_speed_tcp.pdf
http://icfamon.dl.ac.uk/papers/DataTAG-WP2/reports/task1/20021001-Yee.pdf
http://www.riverbed.com/docs/TechOverview-Riverbed-RiOS.pdf
http://packetlife.net/blog/2010/aug/4/tcp-windows-and-window-scaling/
http://en.wikipedia.org/wiki/HSTCP
http://tools.ietf.org/html/rfc1323
http://en.wikipedia.org/wiki/Bandwidth-delay_product
http://en.wikipedia.org/wiki/Round-trip_delay_time
http://community.riverbed.com/t5/Steelhead-Appliance/hs-tcp-questions/td-p/5564
http://cisconet.com/traffic-analysis/traffic-analysis-general/413-internet-speed-issue-why-tcp-window-size-is-matter.html
http://www.networkworld.com/details/7591.html
http://research.microsoft.com/en-us/um/people/padhye/tcpworkshop/slides/raj_jain_high_speed_tcp.pdf
http://icfamon.dl.ac.uk/papers/DataTAG-WP2/reports/task1/20021001-Yee.pdf
WAN Acceleration hardware (and software) from vendors like Riverbed and Cisco have methods to optimize "Elephants" (LFN's or Long Fat Networks).
In Riverbed's case they combine TCP acceleration techniques, such as "Virtual Window Expansion (VWE)" or normal WAN links, but for LFN's (long-haul, high-latency links such as satellite) you can enable HS-TCP (High-Speed TCP - see RFC 3649). When using HS-TCP you need to calculate Bandwidth Delay Product to set the buffers.
VWE is a product of the use of "Scalable Data Reduction", or sending less over the WAN. SDR is not just compression, but clever use of storing data in bit-streams on WAN Accelerator disk and sending only "references" to that data when the same bitstream is requested over the WAN. SO it doesn't matter if the data is sent using FTP, CIFS or HTTP. Clever stuff.
In addition to optimising TCP, Other protocol-specific acceleration techniques can be used as well. "Read Ahead and Write Behind, MAPI pre-population.
The list goes on!
Wednesday, May 9, 2012
Was looking at difference between PC and Mainframe
The Opteron based computers achieved superior performance on a per processor basis. Performance gains were achieved through processor speed improvements and system architecture. When the cost of these Opteron machines was considered, their performance to price ratio is several multiples of the legacy mainframe computers.
http://dl.dropbox.com/u/25830953/nasa-pc-mainframe.pdf
The Opteron based computers achieved superior performance on a per processor basis. Performance gains were achieved through processor speed improvements and system architecture. When the cost of these Opteron machines was considered, their performance to price ratio is several multiples of the legacy mainframe computers.
http://dl.dropbox.com/u/25830953/nasa-pc-mainframe.pdf
A. If you need to create a file of a certain size and the file contents don't matter, you can use the Fsutil command as follows:
fsutil file createnew <name of file> <size in bytes>
For example,
fsutil file createnew d:\temp\1mbfile.txt 1000000
creates a 1MB file named 1mbfile.txt in the d:\temp folder. I've successfully used this command to create a very large file to reduce the amount of free space when I was using a buggy installation program that couldn't address too much free space.
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