Rank() function in sql getting wrong result

Question

 below is my query

 

with A as (select *

,Rank() over(partition by ClientID order by CommunicationLogID desc ) as RNK from Communication)select * from A

where ContactDirectionID > 0 and dayid >= 1887 and dayid<=1887

and RNK=1

 

 

output

RNK

7

1

2

1

2

13

20

1

1

5

6

1

2

3

2

1

12

1

8

2

2

5

7

1

4

10

3

4

1

5

6

2

1

4

2

1

9

18

11

12

13

1

1

2

8

7

2

1

2

1

1

2

1

1

1

1

1

1

2

1

1

1

7

1

1

1

1

5

3

4

2

2

4

1

2

11

12

13

12

5

2

13

14

2

2

4

7

7

1

3

4

5

1

6

9

10

3

1

8

1

3

1

1

4

1

4

1

13

14

1

2

3

3

1

3

2

14

15

5

3

5

1

6

8

1

5

5

4

1

1

1

2

5

2

5

6

7

9

2

13

14

4

4

6

7

5

6

7

8

1

1

1

1

1

2

3

1

1

9

7

 

please help why i am getting this wrong output

 

after 1,2,3,it should start again 1 but suddenly getting 3,7,20,13 and many more

 

why  i am not getting please help me