Speex dev - Apr 2010 - Timestamp for jitter buffer

Hi,

When I insert timestamp to a packet at sender side for receiver's
jitter buffer, can you let me know how to add it?

For example;
  Mode: Narrowband mode
  Sampling Rate: 8 KHz
  Frame size: 160 (20ms frames)

In this case, I think the span of JitterBufferPacket(the timestamp
units) is 160, and should the timestamp be incremented by 1 or 160?  (
0, 1, 2, 3, 4, 5, ..... or  0, 160, 320, 640, ....)

Thank you for your help in advance.

Regards,
Yas