Round-trip delay over the WAN

Unanswered Question
Dec 3rd, 2008
User Badges:

i have Cisco Unified Communication Manager 7.0 with Cisco 7816 Server in Egypt Cairo

and router 2811 with cisco callmanager express software at Algeria

the question is,in case i configured the 2811 router as SRST do the ip phones at Algeria register directly to ccm7.0 at Egypt Cairo over the WAN. and what is the round time delay that is accepted for quarntee the voice quality over the WAN.


i have pinged the 2811 router from cairo and time is over 500ms

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (1 ratings)
Jaime Valencia Wed, 12/03/2008 - 14:20
User Badges:
  • Cisco Employee,
  • Hall of Fame,


the recommendation is 150 ms of one way delay, depending on the scenario up to 400 ms might be acceptable.

was the ping tested using the voice values??? because otherwise if you have QoS configured the ping was not treated as such and only as ICMP traffic and it's useless as the values do not reflect the real delay for voice

check the BW and QoS settings, ask your link provider if they could provide a higher SLA for voice traffic. the real only way to find out if the quality is going to be really bad would be to make a test call.



if this helps, please rate


This Discussion