SIP Traffic and Jitter & shoretel

Posted on 2014-09-15
Last Modified: 2014-11-26
Getting a number of users complaining of poor voice quality.
I have spoken to both our comms and phone suppliers, not much help.

i've been notified of issues at both our sites.  Both sites are configured the same (in terms of hardware) the phone system is shoretel.
The l3 switch going through a cisco asa firewall is an hp 2910 al poe.  Routing all traffic to the firewall.
The only different i can see is the remote site has not got QOS enabled to Differential Services.  SHould this be enabled in order to help jitter at site b?

What else can i check/enable to help with jitter.
Our 10mb links are running at about 2mb on average.
Question by:CHI-LTD
  • 4
  • 2
LVL 15

Accepted Solution

getzjd earned 500 total points
ID: 40325106
Do you have MPLS and COS enabled between those links?
Does this occur both intrasite and intersite?
Have you enabled QoS priority on the hp 2910 for voice traffic?
What is your disserv setting in ShoreTel (call control --> options) ?

Author Comment

ID: 40325594
no we have a 10mb link over vpn.
both sites.
yes, and just enabled diff-serv on the other switch that had issues
LVL 15

Assisted Solution

getzjd earned 500 total points
ID: 40325737
So if a user at site B calls another user also at site B, they receive jitter?    

Do you have QoS applied to the VPN tunnel between sites?   If these are standard internet lines, you will be at the mercy of the internet as soon as your data leaves the modem/router
DevOps Toolchain Recommendations

Read this Gartner Research Note and discover how your IT organization can automate and optimize DevOps processes using a toolchain architecture.


Author Comment

ID: 40327608
no internal seems more reliable.
i believe the firewalls do priority os have say 2mb dedicated to voice.

Author Comment

ID: 40341259
would a higher compress codec e.g. 729 help?

Author Comment

ID: 40415543
would qos on a link thats not being hit hard still help?

Featured Post

VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Sender charges for calling my magicJack Plus service? 3 57
Skype for Business 10 71
How to get Asterisk calls indicators? 2 67
Implementing Cisco Jabber 1 80
Transferring data across the virtual world became simpler but protecting it is becoming a real security challenge.  How to approach cyber security  in today's business world!
Outsource Your Fax Infrastructure to the Cloud (And come out looking like an IT Hero!) Relative to the many demands on today’s IT teams, spending capital, time and resources to maintain physical fax servers and infrastructure is not a high priority.
Sending a Secure fax is easy with eFax Corporate ( First, Just open a new email message.  In the To field, type your recipient's fax number You can even send a secure international fax — just include t…
Internet Business Fax to Email Made Easy - With eFax Corporate (, you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…

920 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now