SIP over leased lines

[EpoUser08]

Id be interested to hear this forums view.

We have a customer who needs SIP trunks. They are getting a 10MB leased line and the data company are saying that they should get a seperate leased line for the telephony, as they are not sure how to guarantee the QoS on the leased line. They say that they can do it for the outbound telephony but cant guarantee how the sip provider will deal with the inbound.

Now clearly it would be preferable to have two leased lines, but are the data co. dodging it slightly and not offering good technical advice for an easy life?

 

[amriddle01]

Unless the SIP providor is the other end of the leased line none of the SIP traffic will be crossing the leased line, it will be going out onto the net

ACSS (SME)
APSS (SME)

http://www.ipoffice.tel

 

[Bas1234]

How many lines?

___________________________________________
It works! Now if only I could remember what I did...

Dain Bramaged
___________________________________________

 

[Bas1234]

Mean sip trunks?

___________________________________________
It works! Now if only I could remember what I did...

Dain Bramaged
___________________________________________

 

[Bas1234]

Meant how sip trunks?

___________________________________________
It works! Now if only I could remember what I did...

Dain Bramaged
___________________________________________

 

[hairlessupportmonkey]

seperate 10Meg leased line for the SIP trunks!

LOL...

10meg leased line would give you over 1000 simultainous calls on the trunk.

I would ask your leased line provider to offer some traffic shaping, e.g, 30x64K calls (Equal to ISDN30), 2.5meg for UDP and the rest for your TCP traffic, e.g general internet, data etc.

As for QoS - I would forget it once it leaves the ISP to your ITSP unless they have some sort of agreed interops.

 

[EpoUser08]

To add some clarity. There are 15x SIP trunks. And the 10MB leased line is for their data- its whether the SIP runs over it as well is the question.

Also, yes there is an interconnect between ITSP and leased line provider.

 

[hairlessupportmonkey]

15 trunks or 15 channels on the trunk?

If you have interops between your ISP and your ITSP then ask them to discuss prioritising your voice traffic over day to day data traffic.

 

[mattKnight]

>If you have interops between your ISP and your ITSP then ask them to discuss prioritising your voice traffic over day to day data traffic.

Apply end to end QoS and you are done! Set your codec to G711 too - with that bandwidth don't settle for less!

However you need to check that the leased line supplier will honour the DSCP flag (EF) and how much EF traffic they will allow without "penalty"

You need to be sure that the QoS is honoured across the entire connection (hence end to end)

Adding a second leased line is good for resilience, but adds extra expense.

Take Care

Matt
I have always wished that my computer would be as easy to use as my telephone.
My wish has come true. I no longer know how to use my telephone.