Length and offset are different numbers
The byte-range form provides a length and can provide an explicit starting offset. A length of 1000 beginning at offset 2000 selects bytes 2000 through 2999 inclusive. The final byte is start plus length minus one. Counting both endpoints avoids a common one-byte error.
When an offset is omitted, the range can continue immediately after the preceding applicable range, under the conditions defined by the HLS specification. It is unsafe to assume that an omitted offset always means zero. The preceding entry and resource relationship matter.
Why repeated URLs can be valid
Consider three logical segments stored in one hypothetical file. Their ranges are 1000 bytes at offset zero, 1500 bytes at offset 1000 and 1200 bytes at offset 2500. They represent different media even though their URI is identical. A diagnostic tool that groups only by URL may hide the distinction.
Likewise, a cache or delivery server must respect how the requests select bytes. A response for the whole file and one for a range have different semantics. Check the request Range field and response Content-Range together when investigating incomplete or unexpectedly large transfers.
What the viewer can conclude
Byte-range packaging does not itself establish lower data usage, greater picture quality or a better connection. It is a way of addressing the media. The bytes still have to arrive in time and be decoded with the applicable media configuration.
A useful technical report records the logical segment position, requested range, status and response range. It should not publish the account-bearing address. If a server ignores ranges and returns the complete file, the player may behave differently depending on implementation; the response must be inspected rather than assuming that any HTTP success is the expected partial transfer.
Questions about this guide
Do identical segment URLs mean duplicate media?
No. Different byte ranges can select different logical segments from the same resource.
Is a byte range a time range?
No. Its numbers count bytes. Playback timing comes from the media and playlist durations.