At current stage, the `ump trasact` used by XCM cannot call the `contribute` function, due to the insufficient maximum weight of the ump service limit.

This proposal hence to increase the weight limit, in order to call more functions such as `contribute`, `staking` and etc. Allowing more ump transacts means provide more flexibility&possibility so to improve the flexibility of parachains, which benefits the use cases of Kusama ecology.

One of [Bifrost](https://bifrost.finance/) service is to help other parachains to participant crowdloan with assets locked while still provide liquidity in the form of our staking derivatives.  We use xcm transact to achieve it with contribution call constructed as following.
```
Xcm::WithdrawAsset {
      assets: vec![MultiAsset::ConcreteFungible {
        id: MultiLocation::Null,
        amount: contribution_amount,
      }],
      effects: vec![Order::BuyExecution {
        fees: MultiAsset::All,
        weight: contribution_weight,
        debt: contribution_debt,
        halt_on_error: true,
        xcm: vec![Xcm::Transact {
          origin_type: OriginKind::SovereignAccount,
          require_weight_at_most: contribution_weight_at_most,
          call: contribution_call,
        }],
}],
````
But the current ump-service-weight threshold does not allow it and the call will just fail.
- Original thread is [HERE](https://matrix.to/#/!WuksvCDImqYSxvNmua:matrix.parity.io/$eoiPfsYmW-za4zCrhGhFEFL2JAaRbG3lFi61sn_Soz4?via=matrix.parity.io&via=matrix.org&via=web3.foundation) 
- The referenda can be found [HERE](https://polkadot.js.org/apps/#/democracy)
- Hash: `0x370695c3d94646368444225c6473fc0081af1a3f08074471d3155ec8497811cf`

 Sets the soft limit for the phase of dispatching dispatchable upward messages.

- The current system used by XCM cannot do certain functions because it doesn't have enough weight.
- This proposal wants to increase the weight limit so that more functions can be done.
- Bifrost is a service that helps other parachains with crowdloan and liquidity.
- The current weight limit doesn't allow Bifrost to work properly.
- There is a referendum to vote on this proposal.

#129 Increasing `ump service limit` threshold value