Taraweeh prayer (Night prayer in Ramadan) is a confirmed Sunnah and it is from Sunnah to perform it in congregation. However, it doesn`t have an Azan or Iqamah; rather, it is called for by any phrase, such as "As-Salatu Jami`ah", "Salatul Qiyam may Allah reward you" or "Salah Salah" and the like.
It is stated in the Shafie book {Bushra Al-Kareem, p.185, by Sa`eid Ba-Ishin}: "In the prayer, which is preferred to be performed in congregation, (Eid prayer, Eclipse prayer, Istisqaa` and Witr of Ramadan) it is recommended to call people to the payer by saying: "Come to prayer", "Salah Salah", Taraweeh may Allah reward you" and it is preferred that people respond by saying "La Hawla Wa La Qhoata Illa Billah."
It is also recommended to take a break after each set of four Rakhas of Taraweeh and for a period equal to the duration of these four Rakhas. In fact, the reason behind calling Taraweeh prayer as such is that the Prophet`s companions used to take a break after each four Rakhas. Moreover, it is allowed, during this break, to make Thikr (Remembrance of Allah), recite Quran or deliver a sermon since Almighty Allah says {What means}: " Men who celebrate the praises of God, standing, sitting, and lying down on their sides, and contemplate the (wonders of) creation in the heavens and the earth.." {Al-Emran, 191}. Similarly, sending blessings on the Prophet (PBUH) is also one of the great acts of worship that bring a Muslim closer to Allah since He the Almighty says {What means}: " God and His angels send blessings on the Prophet: O ye that believe! Send ye blessings on him, and salute him with all respect." {Al-Ahzab, 56}. According to authentic tradition, it is confirmed that the people of Makkah used to perform Tawaf (circumambulating or walking in circles around the Kaaba in an anti-clockwise motion) between each set of four-Rakhas of Taraweeh since this is a good righteous deed.
It is stated in the Shafie book {Moghni Al-Mohtajj, Vol.1:p.461, by Al-Khateeb Al-Shirbini}: "Each set of four Rakhas was called Tarweehah (break) because they used to take a break after performing it."
It is stated in the Hanafi book {Bada`ei Al-Sana`ei`, Vol.1:p.290}: "After each set of four Rakhas of Taraweeh, the Imam rests for a period equal to that set, praising Allah, saying La Ilaha Illa Allah, sending blessings on the Prophet (PBUH) and supplicating. After the four Rakhas of Taraweeh offered before Witr (Witr is an Islamic prayer that is performed at night after Isha or before fajr. Witr has an odd number of raka'at prayed in pairs, with the final raka'ah prayed separately), he waits for the period equal to the duration of these four because this is what the righteous predecessors used to do."
In conclusion, it is recommended to call for Taraweeh by saying "Qiyam/Taraweeh may Allah reward you", "As-Salah Jami`ah" or any other phrase indicating that. It is also recommended to make Thikr, recite Quran and send blessings on the Prophet (PBUH) between each set of four-Rakhas to attain the great reward from Allah particularly in this holy month of Ramadan. And Allah the Almighty knows best.
