No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

SBC to SBC silence call due to static routes

Publication Date:  2012-08-09 Views:  431 Downloads:  0
Issue Description
 In Telenor there are two SBCs (SBC1 and SBC 2) working in loadsharing. Some of International carriers are connected to SBC 1 and some are connected to SBC2. Version of both SBCs are V200R005C03SPC200. Both SBCs were working fine separatedly, but silence call was observed in case of a transit call i.e. when SIP operators connected to SBC1 calls to SIP operator connected to SBC2 or vise versa we face silence issue. Carrier 1----à SIP----àSBC2--à SoftX3000---à SBC2/SBC1--àSIP--àCarrier 2 (Calls face silence)
Alarm Information
NULL
Handling Process
For resolving this issue of silence call, i have performed below steps.
1. I have narrow down my testing to only two carriers and take the scenario as Carrier 1----à SIP----àSBC2--à SoftX3000---à SBC2/SBC1--àSIP--àCarrier 2 .
2. Pinged the media IP of Carriers 2 from both SBC1 & SBC2. Carrier2 was not pinging from SBC1 though it was pinging from SBC 2, so I thought there might be some problem of connectivity between SBC1 & SBC2. After which I have analysed the detail configuration of both SBCs and of LAN switches which were interconnecting them.
3. After detail analysis I found that, static routes were properly configured on both LAN switches but there was no static route of SBC2 media IPs on SBC1 and vise versa on SBC2.
4. After which I have defined static routes of Media IPs of SBC 2 on SBC1 and vise versa on SBC2. After which issue has been resolved.

Root Cause
Both SBCs are working fine independently, so I thought there must be issue between SBC to SBC connectivity. So Pinged the media IP of Carriers 2 from both SBC1 & SBC2. Carrier2 was not pinging from SBC1 though it was pinging from SBC 2, so I thought there should be some problem of connectivity between SBC1 & SBC2. After which I have analysed the detail configuration of both SBCs and of LAN switches which were interconnecting them
 After which I have analysed the whole configuration of both SBCs and LAN switches which were used for interconnecting both SBCs. After detail analysis I found that, static routes were properly configured on both LAN switches but there was no static route of SBC2 media IPs on SBC1 and vise versa on SBC2 for SBC1
<

Suggestions
When ever you find such problem it is suggested to first completely understand the network diagram and call flow and narrow down your testing to one or two operator and start testing by PINGING media IPs.
When you should do configuration on SBCs always save it.

END