Mikoyan-Gurevich MiG-17, part one, the prototypes

When the MiG-15bis was showing the benefits of the swept wing in combat over Korea, the Mikoyan-Gurevich design bureau was already planning its replacement to fix any of the problems encountered in the MiG-15bis. Eventually the result was one of the best transonic fighters intruduced before the advent of the true supersonic types like the North-American F-100 Super Sabre or the Mikoyan-Gurevich MiG-19. The design was still effective in the 1960s when faced subsonic dogfights over Vietnam against much faster planes which weren't optimized for maneuvering in such slower speed and short-range engagements.
Unlike the MiG-15 which had a Match sensor to automatically deploy the airbrakes because it couldn't safely excess the speed of Mach 0.92, the MiG-17 was designed to be controllable at higher Mach numbers.
Even if the MiG-17 strongly resembles the MiG-15, it had an entire new thinner and more highly swept wing and tailplane for speeds approaching Mach 1. While the F-86 Sabre introduced the "all-flying" tailplane, which helped to control the aircraft when close to the speed of sound, that system wasn't adopted by the Soviets until the MiG-19. The wing had a "sickle-sweep" compund shape with a 45º angle like the F-100 Super Sabre near the fuselage and tailplane and a 42º angle for the outboard part of the wings. As the wing was stiffer it tended to resist the tendency to bend its wingtips and loose aerodynamic symmetry unexpectedly at high speeds and high wing loads. As it was strongly based on its predecessor, it inherited a major design deficit which caused its fuel tanks to develop an under-pressure condition when more than half of the tank was used, which could eventually lead to tank implosions, crushing the fuselage in mid-flight, almost always with fatal consequences. Approximately the 30% of the fatal accidents of the MiG-17 were attribuited to that flaw.
Unlike the MiG-15, it had a third wing fence on each wing, a ventral fin and a longer and less tapered rear fuselage which made the aircraft around one meter longer. It was powered by the same engine model as the MiG-15, the Klimov VK-1, and much of the rest of its construction like the forward fuselage, landing gear or gun installation was carried over. The first prototype (shown in the drawing below) flew for the first time on 14th January 1950 at the hand of Ivan Ivashchenko and was called I-330 SI by MiG bureau.
During one of the test flights, Ivashchenko was killed when the aircraft developed flutter which tore off his horizontal tail causing a spin and crash on 17th March 1950. The lack of wing stiffness also leaded to aileron reversal which was quickly discovered and fixed. Additional prototypes were built named SI-2 and experimental series aircraft named SI-02 and SI-01 in 1951 and also tested and were generally successful. On 1st September 1951 the aircraft was accepted for production and was officially given the new designation of MiG-17 as it differed too much from the original MiG-15. It was estimated that with the same engine as the MiG-15, the MiG-17 could be 40-50km/h (24.85-31.06mph) faster and it had greater maneouvrability at high altitude.

Sources:
1. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-17
2. Salamander Books - The Complete Book of Fighters