Contact Center Networking: Offload, Receive Side Scaling and Chimney - Revision history

Gselthof: /* Checking Windows 2008 */

2012-10-19T18:08:03Z

Checking Windows 2008

← Older revision		Revision as of 18:08, 19 October 2012
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	*Open a CMD session with elevated Administrator rights and issue the following command:		*Open a CMD session with elevated Administrator rights and issue the following command:
-	<pre>netsh int sh offload	+	<pre>netsh int ip sh offload
	</pre>		</pre>
	If any offload feature is enabled it will be listed underneath each NIC that it is enabled for.		If any offload feature is enabled it will be listed underneath each NIC that it is enabled for.

Gselthof: /* Checking Windows 2003 */

2012-10-19T18:07:45Z

Checking Windows 2003

← Older revision		Revision as of 18:07, 19 October 2012
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	*Open a CMD session with elevated Administrator rights and issue the following command:		*Open a CMD session with elevated Administrator rights and issue the following command:
-	<pre>netsh int sh offload</pre>	+	<pre>netsh int ip sh offload</pre>
	If any offload feature is enabled it will be listed underneath each NIC that it is enabled for.		If any offload feature is enabled it will be listed underneath each NIC that it is enabled for.

Dosproul: 1 revision

2012-10-05T15:10:54Z

1 revision

← Older revision

Revision as of 15:10, 5 October 2012

Hoturner: /* Cisco's Position on these Settings */

2012-08-02T11:05:15Z

Cisco's Position on these Settings

← Older revision		Revision as of 11:05, 2 August 2012
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	While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>		While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>
		+
		+	= Cisco's Position on these Settings =
		+
		+	Cisco advises that your first step to address any issues that are potentially associated with any of these features is to '''update NIC drivers & firmware'''. If the symptoms persist, then you can look to disable these settings per the instructions below.
		+
		+	'''IMPORTANT!''' While no adverse affect has been reported over time in the field with these changes being made, Cisco hasn't tested the impact of these changes thus cannot guarantee that overall system performance will not be degraded.

	= How to Check they are enabled? =		= How to Check they are enabled? =

Dosproul: 1 revision

2012-07-12T14:28:42Z

1 revision

← Older revision

Revision as of 14:28, 12 July 2012

Hoturner at 14:03, 25 May 2012

2012-05-25T14:03:15Z

← Older revision		Revision as of 14:03, 25 May 2012
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	== Offload: The TCP Offload Engine ==		== Offload: The TCP Offload Engine ==

-	The TCP/IP Offload Engine (TOE) was introduced in the early 1990's, however take up within the industry ~~didn't~~ really start until early 2000. It was originally designed to provide the capability to alleviate the ~~mainbaord~~ processor(s) from performing checksum calculations to ASICs located on a TOE-supporting Network Interface Controller (NIC).	+	The TCP/IP Offload Engine (TOE) was introduced in the early 1990's however take up within the industry did not really start until early 2000. It was originally designed to provide the capability to alleviate the mainboard processor(s) from performing checksum calculations to ASICs located on a TOE-supporting Network Interface Controller (NIC).

	As a general rule of thumb, for TCP/IP it takes 1 CPU cycle (1Hz) to process 1 bit in 1 second. This means that at gigabit speeds, you are looking at roughly 1GHz used to process 1Gb/s of traffic. This is not so much of a problem at FastEthernet or even GigabitEthernet speeds but does become a serious concern with 10GigabitEthernet Networks.<br>		As a general rule of thumb, for TCP/IP it takes 1 CPU cycle (1Hz) to process 1 bit in 1 second. This means that at gigabit speeds, you are looking at roughly 1GHz used to process 1Gb/s of traffic. This is not so much of a problem at FastEthernet or even GigabitEthernet speeds but does become a serious concern with 10GigabitEthernet Networks.<br>

-	== ~~Recieve~~ Side Scaling ==	+	== Receive Side Scaling ==

-	This feature was introduced by Microsoft to prevent all packets from being handled and processed by a single CPU core in a multi-core computer. It uses a complex hashing algorithm to force the routing of packets to different cores.	+	This feature was introduced by Microsoft to prevent all packets from being handled and processed by a single CPU core in a multi-core computer. It uses a complex hashing algorithm to force the routing of packets to different cores.

	== Microsoft TCP Chimney Offload & NetDMA ==		== Microsoft TCP Chimney Offload & NetDMA ==
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	<br>		<br>
-
-	~~= Why is this important? =~~
-
-	While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that plenty of other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>
-

	Please also see:		Please also see:
Line 38:		Line 33:
	[http://msdn.microsoft.com/en-us/library/windows/hardware/gg463253.aspx Receive-Side Scaling Enhancements in Windows Server 2008]		[http://msdn.microsoft.com/en-us/library/windows/hardware/gg463253.aspx Receive-Side Scaling Enhancements in Windows Server 2008]

-	= How to Check if they are enabled? =	+	= Why is this important? =
		+
		+	While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>
		+
		+	= How to Check they are enabled? =

	You have a number of means to check that these features are enabled.		You have a number of means to check that these features are enabled.
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	= How to Disable these features? =		= How to Disable these features? =

-	Depending on the operating system used you will need to disable these features in different places. Below we~~'ve~~ split out the requirements for Windows 2003 and Windows 2008. Note that when we request you disable checksum offload in the Network Interface Card, you should disable '''ANY''' configurable option with the word '''Offload.'''	+	Depending on the operating system used you will need to disable these features in different places. Below we have split out the requirements for Windows 2003 and Windows 2008. Note that when we request you disable checksum offload in the Network Interface Card, you should disable '''ANY''' configurable option with the word '''Offload.'''

-	== Windows 2003 ==	+	== Windows 2003 ==

-	Here is the collated recommendations for Windows 2003 SP2 servers if they are part of a Contact Centre deployment.	+	Here are the collated recommendations for Windows 2003 SP2 servers if they are part of a Contact Centre deployment.

	*NIC Device driver updated to latest version		*NIC Device driver updated to latest version
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	*#Click Configure, and then click the Advanced tab.		*#Click Configure, and then click the Advanced tab.
	*#In the Property list, click Receive Side Scaling, click Disable in the Value list, and then click OK.		*#In the Property list, click Receive Side Scaling, click Disable in the Value list, and then click OK.
-	*#In the Property list, click each Offload option (IPv4 Checksum/TCP Offload/Large Send Offload, etc), click Disable or Off in the Value list, and then click OK. Any option with Offload in the description should be disabled.	+	*#In the Property list, click each Offload option (IPv4 Checksum/TCP Offload/Large Send Offload, etc.), click Disable or Off in the Value list, and then click OK. Any option with Offload in the description should be disabled.
	*#Repeat steps for Public and Private interfaces.		*#Repeat steps for Public and Private interfaces.
	*Check the registry to confirm settings applied after KB patch. You should see the following three registry values:		*Check the registry to confirm settings applied after KB patch. You should see the following three registry values:
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	You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.		You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.

-	'''These changes have shown to provide a significant ~~improvment~~ in buffering and latency issues across private network links.'''	+	'''These changes have shown to provide a significant improvement in buffering and latency issues across private network links.'''

	== <br>Windows 2008 ==		== <br>Windows 2008 ==

Hoturner at 13:42, 25 May 2012

2012-05-25T13:42:51Z

← Older revision		Revision as of 13:42, 25 May 2012
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	You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.		You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.

-	[[Category:Unified_Contact_Center_Enterprise~~]][[Category:Troubleshooting Unified CCE~~]]	+	[[Category:Unified_Contact_Center_Enterprise]]

Hoturner at 13:42, 25 May 2012

2012-05-25T13:42:05Z

← Older revision		Revision as of 13:42, 25 May 2012
Line 157:		Line 157:
	You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.		You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.

-	[[Category:Unified_Contact_Center_Enterprise]]	+	[[Category:Unified_Contact_Center_Enterprise]][[Category:Troubleshooting Unified CCE]]

Hoturner at 13:40, 25 May 2012

2012-05-25T13:40:46Z

← Older revision		Revision as of 13:40, 25 May 2012
Line 156:		Line 156:
	<pre>netsh int ip show offload</pre>		<pre>netsh int ip show offload</pre>
	You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.		You should only see a description of each NIC installed in the server with nothing listed below each NIC entry.
		+
		+	[[Category:Unified_Contact_Center_Enterprise]]

Hoturner at 13:40, 25 May 2012

2012-05-25T13:40:12Z

← Older revision		Revision as of 13:40, 25 May 2012
Line 5:		Line 5:
	== Offload: The TCP Offload Engine ==		== Offload: The TCP Offload Engine ==

-	The TCP/IP Offload Engine (TOE) was introduced in the early 1990's however take up within the industry didn't really start until early 2000. It was originally designed to provide the capability to alleviate the mainbaord processor(s) from performing checksum calculations to ASICs located on a TOE-supporting Network Interface Controller (NIC).	+	The TCP/IP Offload Engine (TOE) was introduced in the early 1990's, however take up within the industry didn't really start until early 2000. It was originally designed to provide the capability to alleviate the mainbaord processor(s) from performing checksum calculations to ASICs located on a TOE-supporting Network Interface Controller (NIC).

	As a general rule of thumb, for TCP/IP it takes 1 CPU cycle (1Hz) to process 1 bit in 1 second. This means that at gigabit speeds, you are looking at roughly 1GHz used to process 1Gb/s of traffic. This is not so much of a problem at FastEthernet or even GigabitEthernet speeds but does become a serious concern with 10GigabitEthernet Networks.<br>		As a general rule of thumb, for TCP/IP it takes 1 CPU cycle (1Hz) to process 1 bit in 1 second. This means that at gigabit speeds, you are looking at roughly 1GHz used to process 1Gb/s of traffic. This is not so much of a problem at FastEthernet or even GigabitEthernet speeds but does become a serious concern with 10GigabitEthernet Networks.<br>
Line 20:		Line 20:

	<br>		<br>
		+
		+	= Why is this important? =
		+
		+	While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that plenty of other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>
		+

	Please also see:		Please also see:
Line 33:		Line 38:
	[http://msdn.microsoft.com/en-us/library/windows/hardware/gg463253.aspx Receive-Side Scaling Enhancements in Windows Server 2008]		[http://msdn.microsoft.com/en-us/library/windows/hardware/gg463253.aspx Receive-Side Scaling Enhancements in Windows Server 2008]

-	~~= Why is this important? =~~	+	= How to Check if they are enabled? =
-		+
-	While the intent of these features is to increase network performance, they have been known to cause significant performance degradation as load increases on Windows 2003 and Windows 2008 servers running any Cisco Unified Contact Center software. Cisco has released a number of field notices regarding these issues and steps to address the settings. There is also plenty of anecdotal evidence on the Internet that plenty of other non-Cisco applications are impacted by inconsistencies between the OS and the TOE-enabled NIC.<br>	+
-		+
-	= How to Check they are enabled? =	+

	You have a number of means to check that these features are enabled.		You have a number of means to check that these features are enabled.