topic Re: SIP Trunk Integration ISP in Call Control

SIP Trunk Integration ISP

ggl277808 — Mon, 26 Feb 2018 16:51:46 GMT

Hi there,

We have recently hired and SIP trunk with an ISP, which has some requirements to allow the flow of calls from customers.

Our scenario is WITHOUT CUBE in between:

SIP TRUNK
(CUCM 10.5) <===================>(ISP)

The provider requires that the ping option within the Profile SIP must be enabled, once set, the ISP indicates us that while the option Max-forward = 0 it does not work, should be set to max-forward = 1.
So, at this moment we're stuck in how to change the Max-Forwards option to 1

I have done some research and I found that using Lua scripting some parameters of the SIP header can be changed, but I have not managed to find how to change the max-forwards option to 1.

find the sip trace option image attached.

Has anyone can give me some clue?

Thanks in advance.

Re: SIP Trunk Integration ISP

ggl277808 — Tue, 27 Feb 2018 08:29:30 GMT

Any help please???!!!

Someone has an idea if it that posible to change this parameter?

Re: SIP Trunk Integration ISP

Mark Stover — Tue, 27 Feb 2018 12:22:39 GMT

Hi Guillermo,

In general, it is not recommended that you connect to a SIP ISP without a border element such as CUBE. Even if you bring up the Pings, you may have trouble connecting media from your phones to the ISP, which typically accept only one or two IP addresses for signalling and media.

If you want to try, you should be able to use the "modifyHeader" function to change that value:

msg:modifyHeader("Max-Forwards", "1")

Re: SIP Trunk Integration ISP

ggl277808 — Tue, 27 Feb 2018 16:12:52 GMT

Hi mstover,

I've solved the issue with the following function:

M={}

function M.outbound_OPTIONS(msg)

msg:modifyHeader("Max-Forwards", 1)

end

return M

Thanks a lot