7925G Random ping times?

[borgiar]

WLC - Cisco 4402

OS - 7.0.98.0

LWAPs - Cisco 3502e

Phones - 7925G

Currently the phones are associating and authenticating, being assigned an IP, and this is where we run into issues.  If you try a "link test"  from the WLC on the client and it fails. If you run a ping from a local device (Laptop, switch, router) or from a remote device I see the same results...

Reply from 10.33.46.85: bytes=32 time=287ms TTL=57
Reply from 10.33.46.85: bytes=32 time=748ms TTL=57
Reply from 10.33.46.85: bytes=32 time=480ms TTL=57
Reply from 10.33.46.85: bytes=32 time=211ms TTL=57
Reply from 10.33.46.85: bytes=32 time=681ms TTL=57
Reply from 10.33.46.85: bytes=32 time=406ms TTL=57
Reply from 10.33.46.85: bytes=32 time=121ms TTL=57
Reply from 10.33.46.85: bytes=32 time=583ms TTL=57
Reply from 10.33.46.85: bytes=32 time=315ms TTL=57
Reply from 10.33.46.85: bytes=32 time=50ms TTL=57
Reply from 10.33.46.85: bytes=32 time=508ms TTL=57
Reply from 10.33.46.85: bytes=32 time=239ms TTL=57
Reply from 10.33.46.85: bytes=32 time=703ms TTL=57
Reply from 10.33.46.85: bytes=32 time=416ms TTL=57

I have gone through the 7925G Deployment guide and made all the recommended settings on the WLC, still no better. We can't make or receive calls.

Any help or direction would be greatly appreciated.

Thanks!

Rich

[Serge Yasmine]

Ping is not a reliable way of testing toward Cisco Wireless IP Phone being 7920, 7921 or 7925. The phone treats this with the lowest possible qos priority.

One thing you will notice is that when the phone is not on call the RTT time is high and when it is on an active call the RTT goes down. This is due to power saving mechanism on the phone.

Going to your problem, you said phone associated and got an ip address, did it also register with CM? If yes and you have your extension displayed, what is the accurate problem?

Thanks

Serge

[borgiar]

Serge,

Thank you for the reply.

The IPT engineers stated the following:

"We couldn't make or receive calls, we had gotten Network busy messages"

I'm not sure how helpful this is, but my understanding is they were able to make a call this morning. I had spent a few hours late last night going through the 7925G Deployment Guide and configuring the WLC based the the Deployment Guide. The changes may have helped. Specifically, the QOS was set to "Gold", I changed it to "Plat". I also removed the require DHCP option.

Thanks again for the reply.

Rich

[Serge Yasmine]

Network busy is due to CAC "Call Admission Control" that is taking place before plaing a call on the Wireless Phones. THis happens when the current serving APs is haivng a lot of clients where there is no more bandwidth available on the AP to assure good quality of service for new call to take place. It is like GSM networks getting busy on new years eve when everyone starts calling eachother to congratulate and the cell of the serving Base Station becomes saturated with calls.

Anyway, as you did, yes, make sure you follow 7925 deplyment guide, pay attention to CAC, QoS, data rates, DTIM, Session timeout and you should be safe.

have a good one

Serge

[migilles]

For the ping times, the 792x phone can sleep up to 1 second when proxy ARP is enabled. This allows the phone to not wake up at DTIM and optimize battery life.

If you want to use ping, ensure the 702x phone is in call.

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