A row erupted after council proposals for new contracts for more than 2,000 staff that would result in wage cuts of up to 23%.
The authority fears it could face equal pay claims from other employees if it does not make the cuts.
Hundreds attended a rally to "celebrate the work of Durham's teaching assistants".
Claire Williams, Northern Regional Secretary of Unison said: "There is positive progress being made... we are really keen to  get a resolution to this dispute quickly for our teaching assistants as it's been a very stressful year for them."
The new contracts were originally proposed for January but after industrial action in November the plan was suspended.
Members of the Unison and ATL unions were due to strike again for three days in December but that was called off to restart talks.
The council says its review of the matter should be completed in September.

McQueen, 20, came through Southampton's youth ranks and has played one first-team game - as a sub against Sunderland in the FA Cup in February 2014.
"As good as the under-21s is, you want to be pushing yourself and the next step for me was playing football," he told BBC Essex.
"I've got the opportunity here so I've got to take it as well as I can."
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Talks held between teaching assistant unions and Durham County Council are "progressing positively", Unison said.
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League One side Southend have signed midfielder Sam McQueen on loan from Southampton for the rest of the season.