T-Mobile Web'n'Walk Box IV/Huawei E970: telephony support?

Looks like the T-Mobile Web'n'Walk Box IV/Huawei E970 is supported by OpenWRT (https://openwrt.org/toh/huawei/e970).
Am I correct to assume that this does not include voice telephony (i.e. GSM gateway) support?

Bonus question: are Huawei/T-Mobile firmware updates available somewhere for that box?