Traffic Shaping on 3725 with T1s

[pmettewie]

Hello,

I am a traffic shaping newcomer and need some guidance as how to BEGIN to approach a problem with traffic.

We have been rolling out Windows 7 at sites and the additional traffic it causes on installation is considerable as it has to request information from our  central site to populate My Documents and Outlook mailboxes.

This has caused some problems on sites as there traffic rates increase to the point that QoS is not sufficient to protect voice traffic and delays and one-way audio are being experienced.

One question is this - is GTS a solution or is CBWFQ within GTS the solution or is something else preferable? The sites involved are data/voice with a variety of routers.

Second question is this - if we have a remote site with a 3725 router as the WAN aggregator with one 4506/Sup IV and one Cat 3550-24-PWR the shaping should be best placed on the 3725, correct? Also, are there issues with shaping incoming/outgoing traffic as I seem to have read?

FYI, the 3725 router has 12.4(8d) with IP VOICE/NO CRYPTO IOS version. The 4506 has 12.1(23)E4 with basic L3 feature set.

Please let me know if more information is needed.

Thanks for your time,

Paul

[Eugene Lau]

Hey Paul,

Here's a good reference and provides a lot of the information that you're asking. It's the SRND - Solutions Reference Network Design for Enterprise QoS

http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html

By GTC - you're referring to Generic Traffic Shaping?

CWBFQ is the newer mechanism for IP based traffic and would typically be applied on the WAN to ensure priority queuing for critical traffic. WAN's are the typical congetions points due to the smaller "pipe" - so QoS policies are very important in managing congestion on WAN's.

Due to the available bandwidth On the LANs, you're less likely to see problems so shaping isn't really a concern. As good practice, QoS should be enabled on the LAN to ensure marking is correct and critical traffic can be queued accordingly out ports. Beyond this, further tuning can be done but you'll need to know exactly what you want to achieve.

HTH

Eugene