7965 off of Remote 881 keeps registering Throughout Day

[Patrick McHenry]

Hi,

A couple of our remote users are saying that during the day, suddenly their 7965 that hangs off their 881 will start registering for 3 to 5 seconds, then it will be fine. Any thoughts?

Thanks, Pat.

[lgijssel]

Might be due to dhcp lease renewal.

Try to increase the lease time to 5 days or more.

regards,

Leo

[Patrick McHenry]

Thanks for the response. I checked the 881 and the lease is set for 24 hours. Any reason I should make it more than that?

If not, any other places to start looking?

- Pat

[lgijssel]

For phones you typically want a long lease time because the renewal can be disruptive if there is a call ongoing.

When set to 24hrs it checks the lease every 12hrs. (half the lease time) And there is one renewal per day.

This can also affect registration status, especially over low bw links.

A longer lease provides the best stability. We set it to 10 days for voip systems by default.

regards,

Leo

[Patrick McHenry]

I will increase the lease time as I suppose it can't do any harm but, are you saying that by having a 24 hour lease time, it could cause disruption even more often than the 12 hour check?

Thanks, Pat.

[lgijssel]

No, not more but if the renewal occurs during office hours users will notice it.

Better to do it less frequent.

If you have a voice vlan, increase the lease time only for that.

One day is quite ok for data.

Leo

[Patrick McHenry]

This is happening more often than just the half life of the renewal so, I think this is happening for a different reason. Any more ideas?

Thanks, Pat.

[lgijssel]

It depends on how reliable the network is.

IP phones are sensitive to packet loss and even jitter.

The problem could be with the WAN link.

You haven't provided many details on that but if the lines are under 256k or perhaps ADSL is used this is a likely suspect.

No QOS for the control traffic is another.

Leo

[Patrick McHenry]

Leo, the connection is Comcast Business class.

It it persists I will call the Carrier.

I provided some sh output.

service-policy voice_and_video

policy-map mark_incoming_traffic

class discover_voip

  set dscp ef

class discover_signaling

  set dscp cs3

class discover_video

  set dscp cs2

class non_voip

  set dscp default

!

policy-map voice_and_video

class call_setup

    bandwidth 32

class internetwork_control

    bandwidth 32

class voice

    priority 128

class video

    priority 460

class class-default

policy-map shaper

class class-default

    shape average 2000000

  service-policy voice_and_video

policy-map mark_incoming_traffic

class discover_voip

  set dscp ef

class discover_signaling

  set dscp cs3

class discover_video

  set dscp cs2

class non_voip

  set dscp default

!

On the tunnel interfaces:

qos pre-classify