Why ISPs are converting PRI to SIP all over Doha Qatar?
SIP is a new technology, better voice clarity, and stability. PRI is old technology and being dropped off by ISPs across the world. The main reason is PRI bandwidth is low and it needs a separate line. SIP comes on the same fiber line in your office ( which already carries internet, IPTV) which can carry 1GB normally. PRI can carry a maximum of 30 channels, but SIP can carry thousands.

Is PRI available everywhere in Qatar
Almost everywhere. Wherever fiber connection available, to be precise. Both Ooredoo and Vodafone providing SIP connections.

What is the price difference between SIP and PRI?
Nothing. Same price for SIP and PRI. Almost QR-1000 per month per 10 channels. 

How soon we can get SIP line ? 
Very quick. PRI used to have delay because they need to pull new cable for that. SIP comes on same Fiber line already there in your office. It’s quick.

Is SIP more clear and stable?
Yes, because the BW of fiber cable is much more than the PRI line.

Will we get same number while converting from PRI to SIP ?
Yes.

Using SIP line, can I connect to international SIP providers internationally?
No. SIP is just an alternative PRI. You cannot uplink directly from SIP line to international providers. You can use your PBAX for that. 

Is there difference in call charges between PRI and SIP ?
No.

What changes we need to make on my PBX in case of PRI to SIP conversion?
Depends of which PBAX you are using now.

Cisco routers, CCME — No change required on hardware. No additional licenses required. Only configuration changes required. Send mail to our support team for configuration changes ( support@htsqatar.com ) 

Avaya IP Office etc. — No change required on hardware. New SIP license required ( SIP Trunk license 10 channels, in case you have 10-Channel line from ISP) .configuration changes also required. Send mail to our support team for configuration changes ( support@htsqatar.com )

3CX  — No change required on hardware. No additional licenses required. Only configuration changes required. Send mail to our support team for configuration changes ( support@htsqatar.com )

Yeastar, Yealink, GrandStream  — No change required on hardware. No additional licenses required. Only configuration changes required. Send mail to our support team for configuration changes ( support@htsqatar.com )

Everyone will eventually move away from Hardware PBXes like Cisco routers and Avaya IP Offices, because primarily it was all designed for ISDN, PRI, or Analog lines. Companies will adapt technologies like Asterisk, 3CX etc because it designed for SIP.