UPDATE Open Issues

Jonathan Rosenberg

dynamicsoft

Glare with PRACK• UPDATE only specifies glare

resolution with UPDATE• Can also glare with PRACK• Rejecting PRACK is bad• Solutions:

– (1) UPDATE wins [NO]– (2) Extend mechanism to PRACK

[Can reject PRACK]– (3) Avoidance: Can’t send UPDATE

if you have sent an answer in 18x for which you have not gotten PRACK

• Proposal: (3)

INV O1

183 A1

PRACK O2

UPDATE O3

Other Issues

• Include 493 Undecipherable?– May require user

intervention to fix

– Proposal: include it, add text saying it retries if it would otherwise retry with that response

• Generate 155 instead of 4xx MAY or SHOULD– SHOULD gives better

services behavior in UPDATE-ignorant proxies