Good Day Friends - need Cisco white papers for best VoIP Network best practices

[gil.guevara]

Hello - would someone be so kind to point us in the right dirction?  We are looking for Cisco's best practices when configuring Cisco switch ports to Cisco VoIP phones to client PC.  Cisco 3750 switch--->Cisco 7960 phone--->Client PC.  We are interested in all considerations - QoS, Duplex settings, phone stettings, client PC settings and etc.  The problem is the environement runs slow for the client PCs and we seems to be uncertain on the formentioned.  Things work well for the client PCs when they are at 100 full on both the switch and PC, but as soon as a phone is in place things slow down and packet loss is happening.

We will also appreciate the same information for WANs too.

[David Hailey]

The CUCM SRND is typically the best starting place IMO.  Take a look here:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/7x/netstruc.html

Hailey

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[gil.guevara]

Many Thanks - what about the plex settings?  3750Full/100-->auto7960auto--->autoClientPC?  we get packet loss everytime we add the phone to the picture and are unsure about the plex settings for each device?

see attached

[David Hailey · Accepted solution]

Auto-negotiation on switch ports, phone, and client PC. I do not hard-code switch ports on access devices unless explicitly required. If you do, then the device connecting to that port should be hard-coded as well.

[gil.guevara]

Cool  - Thanks

What about QoS?  Would that cause the packets from the attached PC to be re-queued?

Also - What is the command string to extend the QoS trust to the PC port on the phone?  I think our issue with packets getting re-queued is QoS related.

[Leo Laohoo]

What about QoS?

We are a Cisco shop.  Routers, switches, phones ... all Cisco (except for the microwave oven).  We leave the QoS off.  No issues.

[David Hailey · Accepted solution]

I admit I have worked in environments without QoS and there were no issues but I would not recommend that to any of my customers.  Implementing proper QoS configurations is considered a best practice pretty much across the board I'd think.  So with that said - Leo, I don't doubt that you experience few (if any) issues, but personally I wouldn't recommend that approach to others.

With that said, I'm not exactly sure what the issue is here except for my understanding based on the brief description you highlighted in your first post.  I also don't know your practices on the network when it comes to configuring switchports (particularly when it comes to speed/duplex settings).  As far as QoS goes and it's role in the issue you're having, I don't really have anything to go on so I won't speculate.

Anyway, to answer your question about how to extend trust to the phone.  There are two commands that you need to use which, if I remember correctly, are:

mls qos trust device cisco-phone

mls qos trust cos

The first command tells the switch to trust a device and specifically a Cisco IP phone.  The second command tells the switch to use CoS (class of service) as the trust mode.

Hailey

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[gil.guevara]

Thanks David - I total agree with you, best practice = QoS.  What is the command to extend the same priorty the phone has to the "PC port" on the phone.

The issue is - when we put a phone between the PC and switch we get segment re-queueing for the PC traffic.   We want to elimenate this.  Thanks

[gil.guevara]

attached is some information from the switch/port and phone

[gil.guevara]

This one has the port config