Normal H-1 requirements:
The H-1B visa is issued to those skilled foreign workers who have a bachelor’s degree or higher in the specialty occupation for which they are being issued the visa. US employers sponsor the foreign worker and file a labor condition application (LCA) with the U.S. Department of Labor, and the employer makes several attestations in the LCA, mainly the following: the H-1B worker is being paid the same wage as U.S. workers who have similar experience and qualifications for that specific employment; employment of the non-immigrant does not adversely affect working conditions of other workers similarly employed;, and notice of filing the application was provided to workers employed in the occupation at the place where the H-1B worker would be employed.
Problems with H-1 visa:
Practitioners and applicants for the H-1B visa find that the most salient problem with the H-1B visa filing is the annual cap. Currently, the visa cap is set at 65,000, with an exemption for 20,000 nonimmigrants who hold master’s degrees or higher. The problem is that the number of applicants greatly outstrips the number of available visas, often resulting in the visa cap being filled on the very first days when filings are accepted.
Therefore, potential H-1B applicants may try to explore alternative methods to enter or stay in the US, without having to deal with the visa cap. One possibility is that worker may come to the US under a B-1 visa. However, this approach is somewhat controversial and not yet widely accepted or understood within the different the government agencies. Consular posts may not know how to properly adjudicate these applications and even if granted, foreign nationals may encounter problems at the port of entry when the Customs and Border Patrol (CBP) officers are not willing to grant them admission. The United States Citizenship & Immigration Services (USCIS) and its predecessor, the legacy Immigration and Nationality Services (INS), have traditionally been hostile to this visa category and viewed it with much skepticism. Therefore, employers and foreign nationals wishing to pursue this visa option should understand the requirements and proceed with caution.
B-1 in lieu of H-1:
A B-1 business visitor visa is a nonimmigrant visa issued to those who visit the US for limited business purposes. Ordinarily, the B-1 visa is not available for those who wish to engage in gainful employment within the US. An H-1B visa, on the other hand, would be an appropriate visa category to allow certain specialized workers to work within the US. The U.S. government has drawn the line for permissible business activity under the B-1 visa as conduct that “is incidental to work that will principally be performed outside out the United States.” Examples of permissible business activities include attending conventions, conferences, and providing consultations.
However, the B-1 visa has an exception explicitly carved out by the Department of State (DOS), which states that “there are cases in which aliens who qualify for H-1 or H-3 visas may more appropriately be classified as B-1 applicants in certain circumstances.” For example, a qualified H-1 visa applicant coming to the United States to perform H-1 services on a temporary, short-term basis typically lasting no longer than six months.
Additional requirements of using the B-1 Visa instead of H-1:
Because the B-1 visa is being used in lieu of the H-1B, DOS has specifically stated that the applicant must fulfill the conditions for an H-1B visa, which includes proving education level and having a job offer and sponsor who needs an employee with the requisite education and/or experience level in the field of expertise, as well as meeting the wage requirements per the LCA. In addition, the B-1 requirement of showing non-immigrant intent is still retained.  Finally, there are unique requirements that are levied on the applicant who wants to substitute a B-1 visa for an H-1B. Those requirements include:
- The applicant must not receive any salary or other remuneration (besides an expense allowance or other reimbursement for incidental expenses) from a US source under the B-1 in lieu of H-1B visa.
- The remuneration must come from a foreign firm, which means an entity with an office abroad and a payroll that is disbursed abroad.
- The employee must customarily be employed by the foreign firm.
- The employing entity must pay the employee’s salary
- The source of the employee’s salary must be abroad.
These requirements narrow the scope of the B-1 in lieu of H-1B visa. Because of these limitations, the evidentiary burden of acquiring a B-1 visa for a potential H-1B is much greater than it would be to acquire either a normal B-1 visa, or an H-1B visa. The B-1 as an alternative to the H-1B is really only viable for international companies that hire workers overseas, then send them to their US branch or subsidiary to perform work on a “specific and finite project.”  Thus, if a US firm is trying to hire an alien in a specialty occupation on domestic soil, they already are unable to take advantage of the B-1 visa.
The filing of a B-1 rather than an H-1B is also a little different. While the H-1B is often filed for an applicant who is already physically present in the US, the B-1 would be filed with a consular officer, who must be satisfied that the applicant meets all the above conditions, including the condition that they are an employee of the overseas company and are being hired to do H-1B caliber work in the states. Thus, the applicant may have difficulty showing that they are employed with an overseas firm if they are hired by the overseas firm and then immediately sent to the US to engage in H-1B caliber labor. If the consular officer is not satisfied as to these requirements, an H-1B application must then be first filed with USCIS.  So far, the empiric evidence indicates that consulates are not very well-acquainted with the practice or requirements of issuing B-1 visas instead of H-1Bs, and this unfamiliarity results in delays and unnecessary denials. 
Finally, even if the visa is issued, one problem is that the Customs and Border Protection officers may not honor the visa and allow the alien to enter the US, either due to the unfamiliarity with the B-1 in lieu of H-1B category, or simply because they do not grant credence to that specific visa category.
Limitations on the B-1 Visa in Lieu of the H-1B visa:
Finally, the B-1 Visa does not allow the same flexibility as the H-1B visa does. The standard duration for a B-1 visa is 6 months, and the H-1B worker under the B-1 visa would have to file for regular extensions of this duration if he wanted to stay. Applicants under the B-1 visa will not be able to change employers in the United States; rather, they will have to maintain employment with the same overseas employer.
 INA 214(i)(1): Except as provided in paragraph (3), for purposes of section 101(a)(15)(H)(i)(b) , 20/ section 101(a)(15)(E)(iii) , and paragraph (2), the term “specialty occupation” means an occupation that requires- (A) theoretical and practical application of a body of highly specialized knowledge, and (B) attainment of a bachelor’s or higher degree in the specific specialty (or its equivalent) as a minimum for entry into the occupation in the United States.
 INA S. 101(a)(15)(B): An alien (other than one coming for the purpose of study or of performing skilled or unskilled labor or as a representative of foreign press, radio, film, or other foreign information media coming to engage in such vocation) having a residence in a foreign country which he has no intention of abandoning and who is visiting the United States temporarily for business or temporarily for pleasure.
 9 FAM 41.31 N. 11.1: Incidental Expenses or Remuneration: Incidental expenses may not exceed the actual reasonable expenses the alien will incur in traveling to and from the event, together with living expenses the alien reasonably can be expected to incur for meals, lodging, laundry, and other basic services.