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high traffic from one gateway to another gateway

Hi everyone,

  We have Observed high traffic between  one gateway to another gateway connected through a MPLS .

here is the brief  overview of  the setup,

1.  We are using a two VG's located in siteA ,this environment also has cucm cluster with a publisher and two  subscribers.close to 35 IPC's used.

2. There is another VG located in siteB , where around 8 IPC's are used.

3. Both the Site A  and Site B are  connected through a separate MPLS link.

SiteA VG's ------>wan interface  site A------->------MPLS------->----------wan interface Site B--------->Site B VG

(source IP)                                                                                                                     (Destination IP)



if call lands in VG of site A,it is treated through CUCM from Site A and if all the phones are in use  then  call transfered to IPCommunicators in Site B through wan interface


if call lands in  VG of site B,it is treated through CUCM from site A and the  transfered to IP communicators in Site B through  wan interface.


High traffic between VG's from Site A to Site B.?


There  should be  no  traffic flow  from VG of site A to VG of site B

Found them to be UDP through packet capture in the Site B 's wan interface.




Re: high traffic from one gateway to another gateway

My suggestion would be to check the MRG/MRGL settings of the IP phones, IP communicators and gateways in CUCM.  Make sure you do not have MTP's being allocated incorrectly.  You may have a scenario where an MTP or Transoder on SiteA's VG is being allocated for calls that come into SiteB's VG and go to IP Communicators at SiteB.  In such a scenario RTP traffic would be sent from SiteB VG to SiteA VG, then back to the IP Communicators at SiteB, effectively traversing the WAN twice.  To check this, the command "show sccp connection" would show you any allocated SCCP resources on your gateway (such as MTP, XCODE or Hardware Conference).  Also, if the VG's are also the WAN routers, you could be allocating MTP on the CUCM itself (which you would not see in the above command).  I hope this helps!